Instructions:O2 now offer an 'Upgrade' service for PAYG phones.
Here's the blurb:
When you upgrade your handset we'll give you 10% of the value of your top-ups as call time worth up to £200 or up to £100 (5%) discount off the price of the handset*.
Based on your top-ups over the past 18 months, or when you last upgraded.
I just got my new W810i from the previous O2 deal thread. Although I only got £3.50 off, there are others who may get loads off. My mum for example has been offered £28 off her next phone! (Which is odd, as I've had my phone LONGER and top up MORE).
Anyway, to get this money off, call 2550 from your mobile (free call) and speak to someone to get some money off!