Terrible customer service

I purchased a clutch kit for my vehicle at the Goldwagen branch in Germiston on the 04 Apr 2015. I also purchased other parts for my vehicle totaling too R7,500. well when i sent my car into the mechanic they said that it was not the clutch that was the problem, so i called them up to ask them if i can return the part as i had no need for it now, so they tell me that they have to charge me a 20% HANDLING FEE on that clutch which was R6700 on its own. I did explain that that part will be returned in the same order i purchased as it was not even taken out the box they said no, i would understand if they clutch was removed from the packaging and actually handled or touched in any way. instead of assisting me or trying to see what they can do to avoid the 20% fee they just said no they cant help. so when i was putting R7500 down on there table they were happy to take my money but in turn to assist the customer when they no longer need the part i find that terrible customer service. so going forward i will no longer shop at a goldwagen store as i have been buying from goldwagen stores for the past 6 years. i will no longer support them as this is how they assist customers.