Please can I get a bit of advice – I bought a ladies bike off ebay for myself. The advert said it had only been used twice and she was selling as she’d had toe surgery and couldn’t ride it. It was in good condition but one of the tyres was deflated – she said because it had been standing unused for so long.

Three weeks later I finally get round to buying a pump, pumped up the tyres and took it for a spin. 2 minutes later there’s an awful noise and the derailleur has detached and the chain has come loose. I take it to a bike shop – they say the derailleur cannot be repaired, they quote me £50 – £60 parts and labour.

I only paid £80 for the bike!

The seller has e-mailed me the receipt – she bought it in September 2014.

What do I do?

Will Halfords replace it?

What if I buy a new one from Halfords but take back the old one a week later saying it’s the one I just bought – can they tell, are there serial numbers?

I asked the bike shop how it happened – they said perhaps it wasn’t set up properly (it says on the receipt that Halfords assembled it) – but the seller did ride it twice since the purchase.

Can I tell Halfords it’s second hand but the seller had only just bought it and they don’t have a receipt?

Please help!