If you are not happy with your power bill or the customer service provided, contact your power company (electricity retailer). If you are not happy with the response from your electricity retailer you can contact Utilities Disputes Limited (UDL), which provides a free and independent complaint resolution service for electricity and gas complaints.
Utilities Disputes Limited
Freephone: 0800 22 33 40
Code of Conduct for Retail Electricity Sales
Some retailers will seek to approach potential customers either by canvasing door to door or cold calling. Some consumers do not welcome this approach. Retailers have agreed a code of conduct for the direct marketing of electricity. This can be found here.