@Pk32 Do you pay for itemised billing ? If you want itemised billing there is a monthly cost for it and itemised billing only starts from the date you request it and it can not be backed dated.
Your other option is to look on your device call history
Or you could request a SAR from EE ( subject access request ). EE have 30 days to provide you this and it will include all the numbers you have dialled or texted. Please read THIS. please note EE can not charge you for this but EE can charge you for the admin work involved in collecting this date.
To contact EE Customer Services dial 150 From your EE mobile or 0800 956 6000 from any other phone.
