4 Digit PIN looking to switch TO Xfinity

I am trying to switch from MINT mobile to Xfinity.  I am in some kind of awful limbo where Xfinity has given me a "temporary"number until my number  is ported over.  I have/had MINT which only gives a 4 digit pin to port my number.  I spoke to about 4 reps for almost 4 hours and nobody can figure out how to port my number since Xfinity requires a 6 digit pin.  We tried front loading with 00's.  I cannot lose my number as I have cancer and all my doctors have my number - among other reasons.  Please help asap - I am so stressed this may have been a mistake.