Returns issues for pool cleaner

I bought the zodiac MX6 combi at builders warehouse in Kempton park on the 13th of Jan 2018

The item was sitting on the promotions section with no consultant selling them, I took it and asked one of the consultants about the product if it was a good buy or not, the consultant informed me that the product was the best and that should I have issues the brand sends people to come and assist

I bought the product and left, got home and installed it, it worked for a few seconds and stopped. I tried it again it never responded. I then installed the old creepy crawler that I have in the house (zodiac creepy brand as well) and the old one works perfectly fine. I then took the product back to the store to ask for an exchange and only then was I informed that the store doesn’t take back pool cleaners. I asked where the policy is because no one informed me of that, it’s not in the receipt nor is it written on the box itself. I was then informed that its not written anywhere ,however they inform the clients(in my case no one informed me since I took the product from the shelf with no assistance)

My issue is that I know the problem is not my pool because the old creepy works perfectly fine, and I do not want the MX6 anymore because it does not meet the requirements, I need to exchange it for a product that I know works

Being told to wait for technicians to come to the house to check it, is a waste of time for me because I know the product is not working, I’ve tested it

Please kindly assist because the 10 day return policy might be app**** should this matter not be resolved within the specified timeframe