This is my first company and I have been working here for almost a year now. It is a small company of about thirty employees and we mostly communicate verbally than through email or other means. When I was interviewed/appointed a year ago I was asked if I would contribute to the organisation for at least two years and I said yes, (I never did sign or make any legal contract/document), but now I have an offer from another pretty big concern and this being an undeniable offer I couldn't resist but talked to my employer about leaving the concern now he refuses to give me a relieving order/letter and says I should continue to contribute for at least two more years in order to get a relieving order, (I could detect a lot of bitterness in his tone).
To add further:- I work night shifts from 9PM to 9AM. Pretty much doesn't leave home if work is pending and provide support like 24*7. I even worked lot of Sundays and practically involved myself in getting the work done. I was the go to guy for any new adventurous tasks now I feel like I've blown it all away. This is the same situation for almost everyone appointed with me but nobody tried leaving till now.
A relieving letter is a formal letter from the employer stating your work period, current CTC and stating that you are relieved from your work as of this date and so on. It is mandatory that I provide it to the new employer else I could be considered as absconded and employers will not hire me.
Is there a way I can convince the one offering a job for not being able to produce any relieving letter? will that be professional to do so?