Sorry to hear that the gap problem was getting worse. That's not a good sign at all!
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Was that with you using the phone in a case? Cos you previously posted pictures of your HO in a clear TPU case.
Great that you have UPS tracking as proof, keep it safe! As heaven forbid if HTC can't find it they will have to reimburse you for the phone.
I was hoping that HTC had changed but if there's horror stories being discussed on FB and other forums that's not a good sign at all.
When you got your phone back the first time round from HTC didn't they forget to switch it off and there were a few marks or stains on the outer body?
It doesn't inspire confidence in HTC and their repairs does it?
I hope all goes well the second time around for you.