I was hired for a 4 months contract and they are willing to hire me permanently. I currently get paid below the market related salary and not getting paid commission like everyone else in my position.I want to know how to get them to increase my salary and still pay commission since they never offered it in the first place..
You could discuss the work you have done in the previous 4 months, and ask your supervisor if he/she was happy with your work. Bring examples of your work to this discussion.
Assuming they were happy, then you should ask to be paid at market value. It could help to have some type of data about what market value is. If you have data that other people are getting commission, use that. I would not use names if they are co-workers, but instead just say co-workers are getting this and that.
Then bring in your previous discussion about your performance and say that based on your performance, you deserve to be paid market value for your position.