If you have a contract with a company, it is more than likely the contract has certain terms when canceling a service. It may specify that you have to send in a contract cancellation letter. The company will have to receive that letter in order to process the cancellation and terminate the service. In your contract cancellation letter, you may want to state that you have fulfilled your end of the
. contract and would like to cease all services with them. If for some reason, you have not fullfilled the contract the company still may render service since you are still under contract irregardless of the cancellation letter.