How do I file a formal complaint?

Switching to Mint, or trying.  Our numbers won't port!  T-Mobile can see the error but don't know what it means so they called Tmobile customer service for help.  Meanwhile, I've explained that my  87 yr Dad's line needs to be restored!  He fell and TMobile cancelled his service without authorization.  How do I get a person to take this seriously and fix it??, it's been 3 days now, and I can't get them to release our phones(Yes all paid off) in order to have working service with another provider.