Gate motor not installed & full refund not given

I contacted Gido Gate Motors [URL Removed] to purchase a new gate motor to replace the existing gate motor on my front gate (10th September 2015). <br> <br> I paid the full price of R4300 upfront and this price included the motor and installation cost. The supplier came out to install the motor and found that the existing motor had a customised shaft so they could not complete the installation. They later said that they could supply another motor compatible with the existing shaft and quoted me R8500. <br> <br> I told the price was high and asked for a refund which they agreed to but deducted R500 as an admin fee! They said it was for the sending out the installers and for not letting them know that the installation would be complicated (how would I possibly know). I was never advised of an admin fee in the initial quotation or told of a fee if the installation was cancelled and the terms and conditions sent to me did not contain this either.<br> <br> With reference to the National Credit Act, I have the right to be refunded the full amount considering that the motor was not installed, it was within the 7 day cooling off period and I did not even take ownership of the goods