[mothered]

so I contacted them today for a phone my cousin ordered 3 months ago saying it never arrived.

If I was the rep, I'd be questioning why you've waited 3 months before getting In contact with the company.

Of course, It's not difficult to come up with a reason.

wondering if they will blacklist the current phone imei?

Apple Itself, may not blacklist It but If the IMEI Is placed In a pool of blacklisted numbers, the carrier will block It when you attempt to connect to their service.