6 years of incorrect electricity meter classification (commercial when should have be

Hey
So recently moved out of a rented apartment in Cork to another in Kildare and discovered when closing my Cork electricity and gas provider account that the electricity meter had been listed incorrectly as a commercial meter and I have been paying as a commercial customer (bizarrely the gas meter for the same apartment was correctly listed as residential). Provider closed account fine but could not advise if I had over or under (hopefully not) paid as a result of this. Provider to contact ESB as they assigned the meter classification incorrectly. I contacted ESB who said they can't assist as it needs to go through the provider!

After over 6 years paying electricity as a commercial entity despite being a resident I wonder should I persue this or would the rates be similar (provider would not comment on this).

Advice appreciated!

Thanks
Alan