Harassment

I have paid up my Credit card, email them the proof of payment and paid up letter from Standard Bank. They keep on phoning me and send sms that I am in arrears. Standard Bank has assured me they have cleared me from them but they keep on harassing me. I don't think the one hand knows what the other hand is doing at this place. I would like them just to stop harassing me. Thank you Piet de Klerk. S/Bank acc no. ********** ********** 54, Ref No. ********** ********** 24.