Toledo Edison review: electric bill overcharging

I notified Toledo Edison several weeks prior to my move from Ohio in April, 2018. They estimated the final reading only (not actual), which I paid. Later they sent a bill correction with the accurate reading. I believe the ‘estimated' reading was intentionally high. Six (6) months later, they have still not refunded me their ‘overcharge'. This is how Toledo Edison treats elderly customers on disability. I wonder how many customers they do this to, and for how long they have been doing it? Maybe it is time for a class action law suit?