Wrong part issued and unprofessional service

I ordered a part from Global Parts online called a VW Vivo dash cup holder. This company sent me the wrong part. I gave them time to get the correct part but they did not get it. For over a month I have been calling them to sort me out, but none of them seemed interested. Not once did they call me back - I had to keep calling them every day. I then asked for a refund. They only refunded me the cost of the part but not the courier cost. I paid R206 to the courier and I wanted this back but they won't refund this to me. They were very unprofessional with this whole transaction. Their names are Mariska and Erika.