ABSA CC Dept ***********, they owe me refund and wont send paid up letter

*********** !!! I am struggling for many months to get a paid up letter from ABSA CC Department and they keep sending us back and forth between million email addresses and telephone numbers, the one more *********** than the next. NOBDY seems to be able to give me the refund owed to me so they can close the account and give me a paid up letter. This is affecting my credit score HUGELY. Credit Card number ***.