Incompetence on MBD

I was handed over to MBD Attorney for not paying my Woolworth visa. I decided to pay them and i requested a settlement letter so that i can pay the debt, i got the letter and it stated i must pay using standard bank account number and i must use my visa card number that appear on the front which i did that. I settled my account on the 26th of October 2020 as i received the letter the same day.I called them on the 28th and 30th of the same month they told me that that the payment has not updated. I called also on the 2nd and 3rd of November 2020 they told me it has not appeared on their side. I asked them what have i done wrong because i did putted the correct account number,amount and reference why don't they see it on their side, they say i putted wrong reference i asked which reference was i supposed to put because the letter stated i must use my visa card number.They said i must send a proof of payment to inquirers and to the lady that send me the letter which i did. no one has contacted me till date to update me. When they wanted the money they called me day and night and now i have settled the account no one is calling me. I'm very disappointed with MBD Attorneys since their the one who gave me the information then later on it seems i'm the one who did a mistake. My credit record is going to go down because of them while i paid in time and all the amount. To make thing worse they said i don't qualify for the discount when i asked them to give me a discount the lady said to me the discount is no longer applicable to me but i never got an notification that i had a discount. I just want the paid up later from them and they also have to update my score in ITC.