Hotspot charge

I had an issue where my phone shutdown. I called support & twice talked to someone that I couldn't figure out what they were saying. Finally I fixed it in the APN (all boxes were blank). Now my phone works but the hotspot didn't come back. 2 more days later tech sent a text saying my phone is not hotspot compatible (although I had it on my phone for 2 years). My problem is I paid my bill 5 days before the problem. I haven't heard 1 word about applying my acct. with credit, and in my acct. it shows I owe my bill with the add on feature still applied. I feel if I don't say anything I'll get ripped off for 10 bucks every month. Not the best time 2 have a costumer think that. I also know the hotspot could've waited till the end of month before removed cuz I know people with it on their phones that are not compatible & they paid their bill 2 weeks before me.