Custom controller sent in for repairs TWICE, looking for advice on how to get refund at...

I'll try to keep this short and sweet.

Bought a 'custom' controller for my husband for Christmas - literally the only thing I did was add his gamertag engraved onto the front.

Got the controller, within a day starts making squeaking noises. We send it back.

Comes back after the first repair, still making squeaking noises. At this point we're thinking it's the casing that's faulty, and we send it in again, with a note specifically to check the casing, and it comes back and is making the same squeaking noise.

Microsoft is playing hardball with us telling us there's no refund option for the controller and telling us to send it in again. We've tried explaining that sending it in will not solve the problem, as it's the custom engraved front casing piece that is
faulty, and we know that they won't replace THAT piece since it's the one piece that is custom.

I am just looking for some advice on how to cut through the red tape to get a satisfactory result, either a new controller with a new front piece that doesn't squeak, or a refund so we can get a new controller that doesn't squeak.

I appreciate anyone's advice/feedback about this.

:)