Not ethical and sales people not trained.

I had a terrible experience with a very expensive item. Their staff is not trained, and they sell products without knowing the technical capabilities. I bought a product with a specific need. They could not comment and said I needed to try it because I have 7days to return. The product was not compatible and on return, they want to deduct 15% for handling and the product is still in new condition with the original box. This was not mentioned at first but they say it is on the back of the till slip. The issue is that you only get the till slip after purchase. The 15% is not shown anywhere in the store. They are rely bad so do not buy from them.