The contract submitted by my employer is different from the offer letter

Hello sir/madam,

I was hired by my employer and the company offer letter was given to me. I worked for 3 months before my visit visa expiry.

Before my visit visa expiry, I was given the last page of the labor contract to sign and give my fingerprint saying it's for my employment visa.

While processing my papers for Emirate ID, I discovered that the salary agreement on the offer letter I received and signed is different from the labor contract submitted by my employer.

Also, working hours were agreed on 9 hours but I work for 12 hours a day with no break.

Finally, when I complained, the boss brought a cancellation letter.