@magsmcg You can read a lot about Comfort Plus on these chat pages, just search for it in the search bar. As for being asked for £200 when the current reading is £79, most of the cost arises in winter, your summer usage is bound to be low, the £200 DD is to pay for the cost of the winter ahead.
Comfort Plus is an expensive system, it is nearly always cheaper to disconnect your storage heaters and use fan heaters of electric fires only in the lounge and bedroom.
The ideal solution is to convert to gas or oil heating but that involves an investment of thousands in new boilers and radiators.
@magsmcg You can tell SP to remove the Comfort Plus system and replace it with a single rate meter. They are obliged to do this if you insist. A gas system would be much better for you.
@magsmcg Well done, if anyone reading this has a wet heating system using electricity they should check if a gas supply is available for the property and switch to gas ASAP.