TxTag Texas Tollways Total Scam!! Website down, phones down, refusing any response. Dallas Texas

TxTag is a total scam. I was sent a bill saying I was in Violation and it was going to be sent to a collection agency if I did not pay. So I went to the website to pay, only the provided account number on the bill 'does not exist'. I tired to call, it told me to call back during normal business hours. I called back, the line was dead/busy. Also, I have a TxTag account with that vehicle on it, and I have already paid this bill. So it appears TxTag is trying to scam me out of $20, refuses to take any calls or email or contact via their website, and is going to damage my credit by giving this to a collection agency even though I've paid the bill and actually have a surplus amount in my account with them. This is a joke of an agency and it should be shut down immediately. Who knows how many innocent Texas they are harrasing and damaging with their incompetence.