British gas a a bunch of Knobbers.
About 5 years ago i apparently changed suppliers to british gas for a period of 28days. For which i owed them the princely sum of £28 odd.
Even after contacting they wouldn't believe i didnt owe them money for these 28days, i believde that a dodgy door to door 'change your supplier' salesman that had come to the door had been doing the old switch and see if you like it and if you dont switch back in 30 days routine without our permission to get the commission. When i challenged this they refused to send me copies of any paperwork.
After supplying them with copies of the bills covering the period from my actual supplier they admitted that there had been an error.
About 6months later and then every 6month approx i received letters from a debt collection agency saying they were going to take me to court over this. Obviously they were not interested in quote " your pathetic excuses we hear every day" and that i would have to take it up with BG either before or while in court...
British gas apparently had 'no power to call them off now the debt had be passed on'. The fact no debt had ever existed didnt seem to matter.
I finally solved the problem by having them served with papers to say i was going to take them (debt collection agency) to court for harassment, and BG with illegally selling on a non-legit debt (not sure of exact clauses - a fine solicitor friend of mine owned them for me).
Needless to say ive never heard anything since...