City of Tallahassee Utilities Electric and water company Charged me $30 for a Typo. Tallahassee Florida

They have an e-bill they were sending me, but it's faulty and wouldn't take my payment. I don't recieve a paper bill, so I called them and told them. They told me to pay online at their website and pay electronically. But they dont take debit cards which are easier and retain the information for future use, so I had to pay by their out-dated elctronic check system with all the different numbers to type in different places. Do you know your routing number and exactly where it is? 

Now they say I made a typo and they didn't recieve my payment from the bank so they threatened to turn off my utilities in five days if I don't pay the regular bill plus $30 more. I had the $133 payment in the bank.That's no problem, but the extra $30 is going to kill and old man on disbility. I just can't afford this. I shouldn't have to pay for their faulty system. Even Comcast handles their electronic billing more efficiently. What am I suppose to do, sell my food stamps? What do I do when I have to eat at the end of the month?