Settlement letter still not received

I had to open an African bank Credit Card account to assist me with my move from Johannesburg to Polokwane, as my Salary wouldn't be paid in time to pay for the move.

So I requested a settlement letter from the USSD service, and I made a full payment on the account. I sent the Proof of payment to them, and requested a letter stating that the full amount was paid, and that the account was closed.

They acknowledged receipt of the POP, and that they are working on my issue, but it is more than a week now, and I still haven't received the letter stating that the account is now closed and paid up.

Customer service doesn't work like this.