No, you cant.
You need the blackberry bolt-on. To get the blackberry bolt-on you need a SIM Only (Simplicity) Plan, or a contract plan.
O2 don't release settings.
They currently do not offer blackberry bolt-ons on PAYG.
If you want to be on PAYG, then get your phone unlocked and go to ORANGE. They DO offer blackberry data plans on PAYG.
Yes, you ring customer services, and if there isnt an option to press a number to go through to technical support, ask the person you speak to for technical support. If they ask why, say you have a problem with your blackberry.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."