Volt benefits not applied to my Virgin Media/O2 Account

I had volt benefits for about a year then it suddenly stopped when my virgin media contract was renewed, havent been able to get volt back even though i have an 02 and a virgin media account, please help.

i cant seem to access the page to apply either, keeps giving me errors, I have been a virgin costumer for years and i thought going to 02 would help me get the most of my virgin contract Can anyone please advise how I can get this resolved. Thank you