Credit Card Money Despairing.

I feel that Nedbank is not in control of their credit department as money goes missing. this is garbage for a bank. i have sent proof of payment to Agnes in Accounts department over 4 times when i ask to deal with someone ells i just end up with old Agnes. and my problem of lost money is still not solved its been 4 months and Nedbank still has not resolved this so my money is missing and they want me to pay the amount again when it was my last installment. this is starting to feel a bit odd as i keep on speaking to the same people maybe they are trying to get extra cash or whatever but this is not right and i want it resolved. Nedbank phones me every second day and i just keep on sending the proof of payments and bank letters stating its paid now they want to start threatening me with ITC when i have made all my payments in full. i wont stand for this and ill go see my attorney to resolve this matter. this is not how they are suppose to treat a loyal customer. i want my missing money found i will not pay the same instrumental twice.