[noir_lord]

I got into a dispute with an electricity company (they later got fined for doing to me what they did to about a million customers...) and I used a similar approach, I kept been polite, firm and finishing everything with "if you can't resolve this matter, can you please refer me to someone who can" and ended up talking to one of their directors.

Amazingly at that point the entire thing was resolved in less than a day and not only did they finally get the billing amount correct but they then waived it entirely.

I never had an issue with paying them what I owed the problem was their figure and mine didn't match and they kept screwing up the collection.