PAID UP LETTER

My account number on my paid up letter differs to the number on the original loan statements hence my loan is still showing outstanding on the credit bureau, i have called several times, emailed several times, requested calls backs but the legal department don't pick up the phones at ALLLLLL, how can a big institution like Finchoice have this kind of service. I paid my account in March of 2022, and still this amount is reflecting as outstanding the full amount of R25000, this affects my credit score so badly, please can someone assists me or get the agents to actually do their job and assist. please email me the paid up letter that states the correct account number # as per the reference number (this is not rocket science)