Bill dispute and bad service from call centre agent

I order online on the 09/09/2017 and mistakenly I chose the wrong delivery address and minutes after order was confirm I sent an email requesting the address to be changed. Nothing was done I than called on the 10th to request it to be changed, spoke of some lady her surname is Govender who promised it will be sorted out and it was never sorted. I than requested for the order to be cancelled and requested for credit in September. The credit has not yet credited until now, I have sent emails and made numerous phone calls and no one is giving me accurate information or responding to my emails. Yesterday I called and spoke to Regan from online shopping department who transferred the call to accounts, where I spoke to a rude, unprofessional lady, her name is Lerato Ntuli. She first did not want to listen to my query instead transferred the call without even letting me know, and than was transferred back to her as per my request. She failed to explain my bill and couldn't answer why the amount due to me had not been credited yet. Instead she gave me her ********* and unprofessional attitude. I have been waiting for more than 2 months for the amount to be credited and and the credit available decreases everyday. I need this to be sorted out asap,