[mothered]

It's the same answer that i received before from the account specialist, so i assume it hasn't been escalated yet. Should i keep pushing for it?

Yes, you've asked the claim be escalated a number of times, and they've failed to comply.

They're obligated to review the claim on request.

On a side note, I have some of the sealing strips. Would this be too late/suspicious to use the sealed box method?

They're expecting the return of the correct Item, In your case, the wrong Item, so It will give them reason to check It when received.