Finchoice paid up letter request

My account with finchoice was settled on both mobi money and 36months which was a nightmare after settling bcs they called me 5 times a day even though the account was settled to a point wherei lost my sanity... Everyday over a month... Theyve still debited my account although it's fully paid up.. I called today requesting a paid up letter and for them to reverse the amount... All sorts of excuse are made with a delay to issue a paid up letter and that I cannot receive it today regardless of the fact that I'm pleading it's urgent as I need to submit to the bank