I'm pulling my hair out with ComEd on a demand billing error that started in January 2018. We've escalated three times, provided all documentation, and they keep saying "under review." Client is getting frustrated and I don't blame them. Anyone have contacts at ComEd that actually get things done?
ComEd dispute - 14 months and counting
ComEd is the worst for long disputes. I had one take 18 months before they finally paid out $42K. Have you filed with the Illinois Commerce Commission yet? Sometimes the threat alone gets them moving. Also try reaching out to their Key Accounts department if it's a large commercial customer.
What's the dollar amount? If it's over $25K I'd seriously consider bringing in legal counsel. ComEd seems to drag their feet hoping people give up, but they settle quick when lawyers get involved. The ICC complaint is definitely worth filing though.
It's about $38K total with interest. I think you're right about legal - this is getting ridiculous. Client is a major manufacturer and they're not happy about the delays. Filing ICC complaint tomorrow and looking for attorney recommendations.