I resided in a place in Ontario about 8 years ago (1999). When I left, the Hydro bill was completely paid. A year and a half later, Hydro contacted me stating that they under-estimated my hydro-usage for approximately 3 years and expected me to pay the bill.

I was dumb and naïve, so I started to pay - only for about 3 months. Then, I contacted a legal-aid and they told me to obtain usage records. I received two different sets of records. Both read different readings and amounts. The legal-aid contacted Hydro for me and told them that I would refrain from paying the remainder due to the former reason.

Hydro stated that they could not obtain accurate readings because the year that I left the residence, they changed their metre reading format. But they still will not close the debt - but they also have not reported it to the credit bureau.

Any words of advice for me to get this off my back and have the debt account closed?

I would make one more try. Have the attorney send them a later saying that; since they cannot prove that your usage was different then previously paid, you expect them to refund the 3 months you paid and mark your account closed. I would include a warning that if they do report this false info to a credit bureau, you will take further legal action.

From there its up to you. If they don't refund and close, you can either either just let it go unless they do report it to the credit bureau. If they do, then you need to pursue it further.