I bought a Nokia N900 secondhand, and the previous owner informed me that it was still under warranty for a further two years. I have had a problem with the mini USB port falling out, and have checked on the Nokia website, it says this is covered under their warranty. The thing is, do I need a receipt for the phone to use the warranty?

No, the handset is under warranty for either 24 months from date of purchase or 25 months from date of manufacture if you don't have the receipt. (It should have told you this when you put the IMEI into the Nokia site?)

It's a known design flaw, should have no problems getting nokia to resolve it.

This is what I did, and then I took it to a Nokia Care Point and the man in the shop refused to fix it, saying it could be stolen.

Contact Nokia, the details can be found on their website or request a warranty repair here: http://www.nokia.co.uk/support/repair/repair

Just been on the website and booked a repair, cannot believe how easy that was! Thank you all for the help x

Yea sadly a lot of service centre's are private companies who are sub contracted by Nokia.

Most cannot actually do real repairs like the one required by yourself so they just send them back to Nokia. They tend to just flash firmware, replace keypads & speakers stuff like that.

no doubt he knew that he could not fix the phone there and prob just wanted rid of you to save on paperwork and hassle.