Quick question regarding returning a dead 360

[Creature]

Bought a pre-owned 360 from a well know high-street store in October and it's just died. Would I be able to take it back and ask for some games for it instead, or would I have to do a straight swap for another 360?

 

[Wyrdo]

Don't you only get 3 months on pre-owned hardware?

Edit: Hmm it looks like it actually might be 12 months