The right to resign without notice and cancel visa for holding or reducing salaries

My office is in Tecom Free Zone. I resigned one month back and now completed the notice period but they didn’t cancel my visa.

My new employer is asking for cancellation papers to get me onboard. The current company is not issuing them, I have faced the below salary reductions in my current organization:

1. Salary deduction of 75% for the month of February

2. Salary deduction of 75% for the month of March

3. Salary deduction of 50% for the month of April

4. Salary deduction of 50% for the month of June.

I am being asked to serve a 3 months’ notice period stating that this is my contractual obligation.

I have requested many a time, it is not possible for me to serve a 3 months’ notice period and I am willing to serve 1 month, not to harm the operations of the organization.

Please advise