Sally used to be the owner of a prosperous dating agency in Brighton. Three years ago she made a contract with Speedy Ltd to advertise her agency on four of their buses for a period of one year. Soon after she had made this contract, Sally decided to terminate her dating agency and become an accountant. She asked Speedy Ltd not to go ahead with the advertisements, but Speedy refused to cancel the agreement, and for the last year has been carrying out its side of the bargain. Last week Sally received a bill from Speedy Ltd for £7000. Advise Sally.