I am having similar problems.  I was an alltel customer - always had great service.  Now with the switch to verison we cannot receive text messages from verison customers only from former alltel customers.  We do have one phone that has a different exchange that can get messages from people with verison.  Our exchange is in an area that had some customers that went to verison and some to another carrier.  I have been on the phone with verison since Tues (July 12th),  first was told it was the tower and that would be fixed in 24 to 48 hours.  Then I was told there is something else wrong.  Put in a ticket on Sat but haven't heard anything.  When I try to get an update on the ticket they say they are still working on it.

We are very frustrated and are tired of being on the phone and getting different answers from different people.  Hope it gets fixed soon.  I would change to a verison plan and phones but it will cost me more money.