Need to Cancel My Account, with No Run Around or Issues

Today our account was shut down. Period. Leaving our business totally in the lurch. No phone service. No warning.  Two people missed phone meetings and inconvenience was experienced by everyone.   

I spent over 35 minutes of the phone trying to unravel when I was disconnected - no phone call was ever placed back to me.

I then spent another 30 minutes trying to unravel with another person on the phone.

Each time I called the business center I was on hold for 5-10 minutes before ever speaking to someone. 

All I know at this point is this:

1. an outstanding check for $464 was received but "something happened" according to AT&T. I don't know what. They said it was NOT "insufficient funds" - but they didn't know what happened
2. My bank never received anything and confirmed there is plenty of money in the account
3. AT&T says they called us "multiple times" using an "auto caller" several times to our VERIZON business number. Our number automatically sends us an email if a message is left, but apparently no message was left by autocaller.
4. I did receive a single voice message on my VERIZON line from the Accounts Receivable Office, but since our account is NOT past due and I had mailed the check for the last payment,   I did not return the call, thinking they had called the wrong account.
5. AT&T did not attempt to reach us on any of the 5 AT&T wireless business numbers we have.
6. AT&T did not attempt to reach us by text on any of the 5 AT&T business numbers we have. 
7. AT&T did not attempt to email us.
8. We have never been late with payment. Never.
9. We pay in full. Always
10. I recently spent hours on the phone with AT&T prior - surely noted on the account- trying to set up a global service for our international travel that would allow us ability to budget clearly for our needs - to no avail.  We now forbit our employees to use AT&T out of the country. Regardless, the account surely noted our active attempts to work with servicing the account. 

Our prior timely payment history alone and the fact that the account was not past due, indicates NO reason to shut off the account without warning.  

I still have not been given an explanation for the inconvenience, huge amounts of disruption in my schedule today to correct this. All I was told - insultingly -  was the I would not be charged to turn the service back on.

Meanwhile, I paid the current account by credit card today, instructed my bank to put a "stop payment" on the open check still  in At&Ts hands for current activity and still  have no explanation.

 I want within 5 business days

• a written apology
  
• a written explanation
• some sort of credit for the hour + I had to take out of my business day - not including the disruption to everyone who works for me and could not use their phone.
  

Sound like I should also contac thet FTC about practices of a AT&T whose almost monopoly allows them to feel they can just shut off service.

Mala