ive not worked for halfords for a few years now so i cant remember exactly, but on the current system they are useing it is possible to view old transactions, the oldest i looked at i think was a year so 2 months should be fine. It can be done in any store but like i said it is time consuming, the more details you have the easier it is to narrow down the search, like estimated time of purcahse, date of purchase ect, and if you used cash or card ect.
did they ask you questions when you purcahsed it for warrenty information so your name and address would have been on the reciept?