Where to file a complaint against ex-employer for not cancelling visa

Where should I file a complaint against my previous company?

I was terminated in Aug 2018, in September I received an emergency and had to travel back home immediately.

I informed the company and we came to an agreement that we shall cancel my residence visa once I am back in the country.

After leaving the country, the next day the company applied for visa cancellation but never finished up the process with Immigration.

Now, it's 8 months of begging them to finish up the process but they have completely refused. I am outside the UAE and I can't make any visa until the company finishes up with visa cancellation at Immigration.

In the system, the residence visa is already cancelled by MOHRE and the labour contract is already cancelled.

The only remaining part is with Immigration and they advised us only the company sponsor or PRO can finish up the process of which they have completely refused.

How do I go about this?