I got turned down by 3 for a contract a while ago for some reason. I wanted a Nokia N95 8GB on a £35 p/m contract and this chap did the first part of the credit check and it came back in an instant as a credit risk. I asked if he was joking as I know I have a brillant credit record and have been told by several companies. Stormed off feeling rather insulted and went over to O2 and within 10 mins walked out with said Nokia N95 8GB on a £35 p/m contract.
To add insult to injury, I have been a 3 customer twice before.