It was my freelance programming job at oDesk in which I missed the deadline. It was a two day job, but after two days 1-2 major bugs were left. So, the client changed all the passwords and refused to pay me anything. The client didn't pay me any upfront or milestone payment. All my 2 day work get wasted and I am feeling that I am cheated.
So, Is it mine mistake or the client is a fraud?
Probably the broader lesson from this is that the terms of the deal were inappropriate from the start. From the looks of it, it appears you have no recourse.
While I'm not familiar with oDesk, I suspect both you and the client have notched up some bad marks on their ratings - you for missed deadlines and them for non-payment. Thus a sour deal is hurting both of you, and if they're not making an effort to meet you in the middle they're going to have problems with subsequent contractors. Only you have an idea how critical that product was - if it was something in their line of business it is probably costing them every day it remains unfinished. In that respect it's in their interest to work out an adjustment so you can get your stuff done and get paid. The more likely scenario if they bring on someone else is that they'll repeat the same mistake, wasting more time and leaving another contractor in the lurch. In some contexts this is described as 'driving by braille' - turn when you hear the tires hitting the curbs.
Imagine that you are about to undergo major surgery, and the doctor is telling you he's going to get you out of there 'on time and on budget'. That's great as long as you survive and go on to live a normal life. In the same respect software development is core to a business process: it is the central nervous system of a business organism. Thus the business prospers when someone with an understanding of the system is working on it, usually this understanding forms over repeated maintenance and development cycles, which in turn requires a high degree of trust between the client and the contractor. Fixed date fixed price contracts don't work very well in this context - they have the potential to make a system that's running half-way OK into a disaster.
If these people are jerks you're better off walking away. If they are good people but inexperienced you should attempt to communicate with them and try to salvage something. You may also have discovered their operation is a mess and not worth bothering with.
In the bigger picture, look at any potential work from the standpoint of utility - is this 'line of business' and mission critical? If so, do everything in your power to arrange a longer term relationship, and bill on a time and materials basis. The upper limit should be a lot more than you actually expect to bill, but you should only bill for work you do, not the total amount allocated. Deliver components and upgrades frequently (weekly, for example) so that the user sees the effects of your efforts week in and week out. As you get close to the agreed limit, discuss extending the budget.
If the utility is marginal - in other words the customer could probably live without it if you can't deliver on the original terms, then you have to calculate a certain amount of risk. Can you afford to do the work without getting paid, if something goes wrong you can't do anything about? If the answer is no, don't commit. This pretty much falls in line with any other form of investment - don't put more into it than you can afford to lose. You might get a good education, but at some point you've got to make a living off your efforts.
Refusal to pay may or may not be an option, depending on how large your failure was. Refusal to communicate is a huge red flag for me. We don't know the details, but it is well possible that your best option is to stop dealing with them.
The other point I would like to draw your attention to is that missed deadline are never spontaneous. If it was 16-hour work, I bet you were aware you won't have enough time approximately half day ahead (e.g., at 75% time point). Not raising this issue in a timely manner is your mutual fault: you should have attempted to contact them as soon as you noticed any risks, and the manager who's responsible to communicate with you should also have contacted you at least twice a day.
I would split your goals into two essential parts:
As a contractor, you probably have signed some work agreement, and it probably contains terms on what to do if partial failure happens. If it has, you just do what the contract says.
If not, you would probably like to get in contact with them and arrange what to do. oDesk dispute team will not help you getting paid, but they will certainly support your attempts to at least get in contact with your employer. We don't know how you will settle this, but you should try at least.
You may also decide to forget about this employer. As I told, two-days work is not that big. If they refuse to communicate, they probably don't want the problem solved. You may expend your time into another work instead.
For the future, you should not get disappointed. Everyone fails, the difference is whether you learn from your mistakes. Here's your lesson:
So, Is it mine mistake or the client is a fraud?
It's your mistake that you accepted a fixed price contract, which isn't "guaranteed" by oDesk. And it's your mistake that the terms of your contract didn't explicitly state what should happen at the end of the 2 day job if any bugs remained.
But it still sounds like the client is cheating you.
You should file a complaint with oDesk anyway. Since their "guarantee" doesn't cover fixed price contracts, you probably won't get anywhere, but you never know.
Good luck.
