Not good, whilst the law is there to protect the public from unfair tradesmen it can be misused, as in this case, to fleece innocent businesses which should not be possible.
The attached pdf (if the forum allows it) is the schedules 2 and 3 from the legislation that details the information you need to supply.
If you supply a fully featured quote or estimate with your business details on it then the following additional wording could be used to cover the provision of an off premises service contract.
However it is critical that you asses the information needed and ensure you are covered for what you do. This is just an example.
Right to cancel
You have the right to cancel this contract within 14 days without giving any reason. The cancellation period will expire after 14 days from the day of acceptance.
To do so you must clearly inform the company of your decision to cancel this contract (by email or equivalent) before the cancellation period expires.
If you cancel (apart from deductions for loss of value from handling beyond establishing the nature, characteristics and function of the goods and delivery charges above standard delivery) the company will reimburse all payments received from the customer within 14 days or less of the return of goods, if applicable, or the receipt of the cancellation notice, by the original method of payment unless agreed otherwise. Goods must be sent back by the customer within 14 days of the date of cancellation, you will have to bear the direct cost of returning such goods.
If service is requested to start during the cancellation period the customer will pay, in relation to the cost of the contract, a proportional amount relating to the work done until the cancellation took place.