Service does not exist

I bought an Xbox one Controller from them in canal walk and found that the A key doesnt work well. I took it to them and one of their staff Ricardo tested it and had the same issue. They swapped it out and now both the A and X key was doing the same thing. They then sent it of to get tested but the regional manager and it came back no faulty found.

I have tested this with multiple people, aswell as tested it on wireless and cable and the issue is the same.

Now they refuse to do anything about. No refund even though i brought it back within 15 days.