So, another very disappointing interaction with the Ambassador call center. Details below, but bottom line is different agents are giving different info, and promised follow up phone call / resolution never happened.

Called to redeem a TP. Friendly agent readily admitted she had never done this before but would call support to find out how to do it. I was fine with that, told her that they seem to be "tricky" and to take her time.
After 30 minutes on the phone, it still wasn't complete and I was told the systems take time to recognize the certificate issuance but she would take care of everything and would call me when complete.
After a couple hours, she called back hotel reservation seemed OK, but United miles were not deposited into my account. She told me told they take 24 hours to post but assured me they would be in my account the next day.

After 48 hours, still no miles in account. Called back and of course got a different agent who immediate told me miles take up to 7 days to post. When I informed her the last agent said it would be in my account in 24 hours, she promised to contact that agent as well as confirm when I can get the miles posted and would call me back with an update. Never got a phone call. Still no miles in account.

Just tried calling again. After the automated greeting and the usual survey prompt, it transfers to an open line, no agent ever comes on. So now sent an email asking for someone to call me.