Getting clearance from the bank after settlement of debt

Hello there,

I left the UAE in 2015 and I had a loan and credit cards paid one by one and left now with the last credit card with a bank. I was paying minimum account until Feb 2020.

Then COVID-19 hit and I was not able to pay. I contacted bank but no response from their end for settlement.

Now suddenly an agency started dealing with me and asking me to pay around AED 12000 which is very difficult. Please advise.

I paid one bank and got clearance, paid another bank but they are not giving out a clearance letter still after much follow up. What can be done?