Oh damn.
First of all, were you able to make the appointment? Or is the clinic totally refusing all info and refusing to schedule?
If so, you could send them a written letter, signed, requesting to inspect your records in full, and cite their privacy practices notice - many have the notice online, and the clinic should also provide one easily upon request.
Did the clinic have a signed consent form to transfer the records to another clinic? They should have required that. If they did obtain this form, and your wife completed it fraudulently, then sadly, the responsibility would fall on your wife for committing fraud... Hopefully wherever they sent the records is a HIPAA protected location though, and that location should provide you a copy of anything upon your request.
Did you file an internal complaint with the clinic? or with OCR with HHS as a HIPAA grievance?
All around a crappy situation. I'm so sorry you are going through this. I hope they call you bad soon and say "oh, our mistake..." and provide you what you need quickly!