If you ask to speak to Payment Management, they will be able to confirm the last payment amount and date for you if that's all that you need, as this information forms part of the financial records which need to be kept for much longer - usually 6 years+.
Although absolutely spot on that it's unlikely other account info would still be held, notes etc. as these would have been destroyed under the DPA requirement to only store information for as long as necessary.
I work for O2, however any advice or opinion given in this community should be considered my own and not necessarily representative of Telefónica UK Limited.
