Taking advantage of customers

Purchased an access point from Computer Mania Blue route in good faith. Internet has been up and down and after about 2 months at my wits end, got in a professional networking company. Turns out the access point that they sold to me was old technology and that is the problem. When I approached Computer Mania and told them they had sold me something that was not the correct item for my requirements they say: Sorry we cannot do anything about it, try selling it on Gumtree?? As a layman, you trust that the consultants are there to help, give the correct information and not offload old stock onto unsuspecting customers. BIG FAIL COMPUTER MANIA!!!