They told me that anything which is sent to me that I did not order is seen as a gift and may be accepted as such. It is also an offence for them to demand payment for something which you receive but did not order
Chazza - that applies to goods addressed to you and with a bill for future payment if you decide to keep the goods.
They hope that you will either want the goods and so pay up, or be to lazy to return them so decide to keep them. It used to be very common, less so with the change in law.
Goods genuinely sent in error do not fall into this category and the recipient has no right to them.