Victoria I cannot believe this is still going on, refusing a check meter, denying your complaint, refusing a letter of acknowledgment. You should escalate this as much as you can and aim for a massive compensation.
Had a meter fitted on Saturday and have used nearly all my months useage already according to the meter HELP I can't afford for my bills to start going through the roof!!
What do you mean by the meter? If it is the IHD display you cannot rely on them for costs, look at the real meter readings and you will be reassured.