Said he's from O2 Airtime calling to renew our contract, (which is by coincidence up for renewal). He asked to speak to "the person that deals with your mobile phones" and as other commentors have mentioned, He knew no details or the account holders name. He was asked to call again Friday afternoon. About 2 hrs later he rang again and had no recollection of his previous call!!! He was just following up from an automated database!!!
Claim to be O2 Airtime, Partners of O2. Wanted to renew the contract but didn't appear to know all our details, And asked NO security questions at all, Not even for the account holders name. This seemed dubious to me so I rand 02 direct and dealt with them.