BEING **********!!!!!!!!!

EXTREMELY FRUSTRATING! I was handed over to this firm by woolworths, I made arrangements to pay in store, in that time MBD NEVER gave any correspondence, no sms no calls. Very conveniently when I paid off woolies in December, MBD phones saying I still owe R585. I made arrangements to pay R280 on the 2018.01.31. MBD started calling to say they was reminding me, I told them NOT to call or sms as I have already made arrangements, Now I hear that my balance is R670. I asked them how, and they are telling me for collections. Question? What collection when my woolies is R0. I already made arrangements to settle their account, Now they telling me that the money of R280 is not reflecting, altho I paid in Standard Bank! It seems I am being billed each time they call me, inspite of already making arrangements and me telling them not to phone me. If i defaulted then I can understand the calls and sms's, It seems like they are ripping me off BIG TIME!