Account cancellation without notice

My bank which issued the card used for auto-payment had mistakenly cancelled the card without notifying me. As a cascading effect, the auto-payment for my AT&T account was no longer valid.

My service suddenly stopped today without any prior notice or warning by AT&T. Several hours later, I have realized that the bill was over due by 2 days. I had difficulties logging in, as my number didn't appear to be valid any more, but after having a new id issued, I was able to pay the balance.

However, I was horrified to notice that the account was cancelled. Will the account be reinstated? Will I be able to get the same number? Notifying all the parties about my phone number would be a nightmare scenario.