Ryobi not helpful

I mistakenly bought a power cable for my ****eater when i was meant to buy something else and when i tried to return it they first said they cant as they doing a stock take then he said that they couldnt process it now as it has a procedure that needs to be follwed and that only happens on tuesday and thursday and it will only be happen next week. Then the sale person goes away and comes back and tells me that they don't do refunds as there is nothing wrong with the product. When I asked where this policy was written he didn't answer me. I find this level of service poor at best .