888-381-9763

Some telemarketing robocall from some mortgage company.

Making stuff up and guessing won't help anyone figure out who really called. The idea is to post something useful towards who might have called, not about not knowing anything.
Here, this might be useful:
Missed calls could be from anyone.
Scammers, telemarketers, debt collectors, pranksters, etc. often use neighbor spoofing so it appears that an incoming call is coming from a local number, or spoof a number from a company or a government agency that you may already know and trust. If you answer, some may use scam scripts to try to steal your money or valuable personal information, which can be used in fraudulent activity.
https://www.fcc.gov/spoofing