No interest to correct mistakes made

We bought two new Explora decoders 2 January 2015. When we arrived home the secondary decoder was not working. We took it back all the way to Multichoice head office and was told the software update on it was not done as it should have been done when we bought it. The software upgrade was then done at the head office. We were then charged for a new smartcard! We received NO new smartcard, a software upgrade was done on a brand new decoder. I have now phoned four times to explain and have the charge reversed. I was told three time that the charge will be reversed. It has not been done. I can not talk to a senior person as they are always in a meeting. I can not receive anything in writing from the call centre as I am told they do not have email facilities. Lastly I was told that I must drive the 50km back to their head office to have a mistake they made rectified. Why? Is anybody at Multichoice interested and capable in resolving this very simple matter?