Can't access all email since migration! Billed for 365 without my knowledge! 15 yr Comcast Customer

This migration has been a nightmare.  I can't get access to all my emails.  Says the server has timed out!! If I do a search in my emails it sometimes brings up the emails but only for the last 2 weeks.  Customer for over 15 years however I have Fios for personal use.  Fios doesn't have these issues whatsoever.  Can't conduct my business. This is unbelievable that they are having these issues and can't or won't do anything about them.  They can't claim they didn't know about the issues because the compaints are all over the internet and these forums. Don't want to switch but can't afford to lose customers because of their blunders!!! 

Fed up!!