Text message problems - delayed message/'Unknown' Sender

I'm hoping someone here can help with me with some text message issues.

I was in a meeting all afternoon yesterday. When it was over, I was a bit surprised to see that I didn't have any text/imessages. I figured it was just a slow afternoon. I sent and received a few messages last evening - no problem.

At about 930 my phone blew up. There were literally 130 messages that came through time stamped from 1:30pm through 9pm. I hadn't changed any of the settings on my phone. But it was literally like when you turn on service after a flight and get hit with a barrage of messages.

I powered my phone on and off. I immediately got hit with 97 texts from 'Unknown' that just said 'Message Not Found.'

If I turn my phone on and off - it'll get the same 97 texts. I went through AT&T tech support who verified my carrier settings (latest) and iOS settings (latest) then had me do a soft reboot. 97 messages came through again.

Today I'm concerned that I'm not getting work related messages that I should...and am going to be hit with another barrage of backed up messages tonight.

Has anybody experienced this?

 

After the first time gap there was a flurry of real messages that came through.

Since then it's just been batches of empty messages when I reboot. I since there hasn't been anything obviously missed from work - I think it's like a cache of the messages that got backlogged - but since I deleted them they aren't matching up so it's saying 'message not found'