Fifty days ago I discovered that for nine years I had been paying commercial water rates for my private flat.The monthly charges for a single person worked out at £32 a month.I contacted Anglia Water & they dropped the charges to £12.Every time I call them they tell me they are still working out how much they owe me. My question is how to I draft a letter & who do I post it to? Because of the delay I want a cash refund;some form of compensation;And 5% interest over nine years. Can some-one give me some advice on this one?