Refuse to cancel my credit card

After trying to close my credit card and having no joy at all, I have to come and expose these people, I am so frustrated. I called in on the 29/08/18 for a settlement amount, next day I paid it and requested closure of my account, then on the 3/9/18 was told they cannot close my account because I didnt pay what needed to be paid, when infact I paid the exact amount that was given, I was told they would investigate, no feedback was recieved. I called back on the 13th with the name of the person assisting me know one knows the person ( they dont give references for calls but was given the name, mmm) NEW AGENT told me she will investigate and get back to me, today the 19/9/18 I call looking for this person, no one knows her (mmmmm) NEW AGENT TO INVESTIGATE.... THESE PEOPLE DONT WANT TO CLOSE MY ACCOUNT!!!!!! WORST CREDIT PROVIDER, DO NOT TRY THEM