Okay, I'm not a UK lockie, but from Finland, so I'll just give a comparison
In Finland there is a sort of "consumer protection law". It provides a clause, that within a reasonable, expectable time from purchase, the product is to be fixed without cost if there is manufacturing error or some other not-wear-and-tear -error. The law only works between the end user and a company, but the consumer can ask for refund or the replacement of product or fixing it from the company the product was purchased or manufacturer or the importing firm.
The expected living time for things is arbitrary, but mostly goes hand in hand with price. For example, a basic 600 EUR TV should last for five years without errors or faults. And if a product is sold for customer with false statements about the product, the customer has the right to get his money back, even the phone calls made for solving the problem can be asked for the company to pay.
The company can provide a guarantee other than what the law provides for customer, for example a guarantee longer than what you'd expect by the law.
And because the locks sold and installed in Finland are basically only Abloys, the Abloys guarentee for their products is what locksmiths provide to the end user.
This whole thing might seem a little "what the lock", but it is good and works and prevents the companies from pissing the customers
