pearly boise:
As a business customer you would have been tied to a contract but not tied for ever. You need to obtain your contract and see what period and what rates you have signed up to.
There are possible answers to most of your concerns but its pointless discussing without knowing the tariff details, meter readings, and certain contract details such as contract length and requirements for notifying tariff changes and arrangements for contract renewal.
Unfortuanately I think you have allowed yourself to be unscrupulously conned.