My sister-in-law who's just moved to London wanted to buy a pay as you go SIM card only, as she already has a phone. It was meant to be a temporary thing before she signed up for a monthly payment plan. Of course I suggested 3. So off we went to their store in Bayswater, London. However, I was quite surprised when I found out that they didn't have any pay as you go sim card in stock.
Further down the road there's a Phones 4 U shop and they eventually bought the 3 sim card from there.
This is yet another example of a 3 store disappointing me. My previous experience was buying a phone from their Coventry store. Yet another reason for interested customers to buy phones or SIM card from their online store.