is that the shop has the right to dispose of uncollected goods under the terms of the Torts (Interference with Goods) Act 1977.
The longer answer is that before it may legally do so it must follow a certain procedure.
1. The trader must first give you notice stating that the goods are ready for collection. The notice must include the following information:-
a) The name and address of the shop b)A description of the goods c) A statement saying that the goods are ready for collection d)The address from where the goods can be collected e)the amount owing.
2. If you do not collect your goods the shop must send you a further statement (by recorded or registered post)informing you that it intends to sell or otherwise dispose of your goods. This statement must include all the information in the first statement, plus the intended date of sale or disposal.
3. If you still don't collect the goods the sale may proceed, but only after a 'reasonable' (that word again) time. In practice the period must be long enough for you to collect the goods, but if a payment is due then the period between the second letter and the sale must not be less than three months.
If the trader does sell your goods you are entitled by law to claim the proceeds of the sale, less any costs, such as advertising the goods for sale. If the trader sells your goods without following the procedure I've outlined you may have a case for claiming compensation, but be warned that it can be very difficult to fight such a case.
In your situation it looks as if your friend may be able to claim the proceeds, as the trader may not have followed the legal steps required. It will hinge around whether a written notice was sent to the postal address provided, and the trader should be able to produce evidence of this if it was done.
Some traders - shoe repairers for instance - would find it economically unworkable to follow the procedure I've outlined. The cost of a shoe repair might be relatively small, compared to the administrative costs involved in complying, and I'm inclined to think that a court would think it reasonable that a 60-day notice was given to everyone leaving shoes for repair. Whether or not this would apply to a laptop is doubtful, and I would think it might be worth your friend's while to push the retailer quite hard about it.
As always, it's his/her decision - I've simply outlined the legal situation.