Std bank is preventing me from making payments !!

Firstly I did not recieve an email or letter from std bank to say that my debt has been sold to MBD. Only after calling the credit card legal department to make pmts ( 3 times) was i told by the agents that they are unable to give me information as my debt was sold. The last agent i spoke to ( Denver , 26/03/2018 at 14:03) confirmed that std bank will not send me any correspondence to confirm that the debt has been sold to MBD. His superior Moosa Nyathi also confirmed that its not in their policy to send such letters - nobody can explain why( do you not give your agents and leaders product knowledge training?) Moosa then said he will request for statements to be sent to me immediately (48hrs) and I am yet to receive such statements! All i want is a letter to confirm that the debt is with MBD and the correct banking details so i can make payments into the correct account !! What is so difficult in sending out a legal letter?!