Service is turned off for non payment but system will not allow payment due to credit on account

My service has been turned off for nonpayment for the second day in a row for past due amount. However my account has a credit on it and I can't even make a payment to try to get the service turned back on. I was able to chat with a live agent yesterday to get my service turned back on and they assured me that I did have credit on my account and it should not be past due. They also assured me that they would put in a ticket to get my account fixed and it would be updated in an hour. This of course never happened and now my service is turned off again. I tried to make a payment today just to get service and then be able to fix this yet again but both the app and the phone system will not allow me to make a payment as I have a credit still on my account.