Dissatisfied with Mr Price MOF service

I am not happy with the service I am getting from Mr Price at Mall of Africa, they are giving me a hassle when I ask for my refund because the transaction went through on my side and my bank does confirm that the transaction went through and was processed by Mr Price on the *** but they say that the transaction did not approve on their end. Sam the store manager is non chalant about it and has been giving me hard time with the refund even after Zimkhitha called the bank for authorisation to refund my money. Please help I still haven’t gotten help and I can’t get through to Mr Price head office.