Holidays:  Cancellation of the holiday by the organiser or operator
If the organiser or operator cancels the holiday or alters a term of the contract, including the price or type of accommodation, the consumer must be given the option of one of the following:

A replacement holiday of equivalent or superior quality - A lower grade holiday, with a reimbursement of the difference in price - A full refund from the site

So whether you are buying or selling a car - holiday - Financial package, or paying for telephones, electricity etc. excellent advice is available on Citizens Information, Consumer Affairs