Acer Aspire 5920 — laptop stopped working

i purchased my acer aspire 5920 laptop online from argos ltd on 08/04/2009 and on 30/09/2009 it stopped working .it has disk read error in it. i phoned acer technical support on the no.[protected] and they asked me to fax the receipt of laptop which i purchased online. i faxed them the copy of label which i got from the bag of my laptop when i got it delivered to my house as i had only that proof of purchase because when you buy something online you don't get receipt for that. they said that we can't do anything without receipt.now i went to argos and asked for receipt and they said they dont have receipt as it was purchased online. what should i do now.