
I tried to buy a 3 phone in superdrug once. I really tried, but first they would not take my visa debit card (nor cash??), then their paperwork was out of sync with the huge posters and finally they couldn't tell me how easy it would be to unblock it for international calls (as i have to make lots).
All in all, despite me being patient and willing they just couldn't sell me a phone.
.... so i went next door to carphonewarehouse and bought it there, obviously not on a 3 contract though. Phew, thankfully i went for vodafone who are predictably expensive but their coverage is really unbeaten.