I'm sinking deeper into depression because of MTN

MTN refusing for me settle my contract account and close it.

It's been over 2 weeks now trying to get a settlement letter from MTN in order for me to settle the account and close it. I took out a contract with them in 2021 and for some months in 2022 I was unable to pay the account until it was handed over to MBD. I explained the situation to my employer that I am struggling to pay my debts because my husband had loss of income since Covid then my employer requested I submit all the settlement letters from the creditors I owe in order for them to settle them for me, I got all other settlement letters from other credit providers within 24 hours however with MTN I sent emails to customer care, legal department, MBD and engaged on social media with their teams but still over 2 weeks I did not get the letter. They insist that I must pay only the arrears amount and Continue with the contract despite explaining that I can't afford it anymore. The most unfortunate part is that my employer can't pay the other credit providers until I submit all the letters including the one from MTN because they want me to be fully debt free. I am sinking into depression due to this and honestly I hate mtn for doing this to me and my family because now I can't even afford school fees and this was my only chance to get my life on track again.