Wee update for you all. I got an email on Thursday night asking me to review my purchase, so I said that the battery was fine, but I was surprised and disappointed that there was no trade discount.

Got a call on Friday telling me the problem was because I had done Reserve & Collect and the Halfords system won't let you combine "offers", hence no discount but the store should have cancelled my R&C order and made the purchase a new transaction.

Anyway, I was in town this afternoon so stopped at Halfords and got £22 back and a free bottle of screenwash. That means the Halfords price for the battery wasn't quite the cheapest but close enough given the convenience factor.

More importantly, I liked the way they owned up to a mistake and sorted it out quickly and without a fuss. Well done Halfords!