CREDIT CARD STILL NOT CLOSED

I took credit card with FNB 3 months ago, and then i realise i am putting myself in unnecessary debts and the early September i settled the whole amount and called the call centre, i followed up after 7 working days as they suggested and it was not closed, they told me they still busy with the matter they apologise and i followed up again after five days as per their advise and still not closed and i again called monday they advised it will be closed within two days, and then i called yesterday and it is still not closed. and i had extra amount as i paid more to the card which it should be credited to me after closure of the card and i notice that they deducted money i am not sure what for, can someone explain to me WHY IS IT EASY TO OPEN DEBTS AND SO DIFFICULT TO CLOSE, HOW LONG DOES IT TAKE TO CLOSE THE CREDIT CARD. i am very dissappointed on fnb i banked with them since i was a student, and i am not going to get tempeted if they think i will I DO NOT WANT CREDIT CARD. can you please make sure this card is closed someone is not doing his or her job that is why i decided to cry out loud.