Big store attitude

On 31st March 2015, at 11 o'clock I purchased a bench grinder from Builders Warehouse in Somerset West. That same morning I tried it out and when I switched it off, it shocked me. Tried it again, same result.<br> Contacted the store via phone and was told to bring it in. I answered by saying that they should collect it. Why should I waste R50. on petrol etc and spend hours of my time to return goods which were defect. Builders Warehouse are adamant that I bring it in, which I refuse.<br> This is the status quo at present.