Most of the ISP can downgrade your package if you are unable to get the level of service for the high-end package you are paying. They asses the speed of broadband that is expected from the package during the first month of installation and move you down to a cheaper plan if required.

Still people, who have entered in to a 12 month contract, experience speed and reliability problems. In such cases contact the ISP to resolve your problems. If they do not solve the issue with in three months you can approach Ofcom with your complaint. You may be able to terminate your contract without paying a cancellation fee, if you are able to establish that the service provider has breached contractual agreements on service.