Ive used the online chat to claim it. i was Payg previously and just signed up for a contract a few days ago, it didnt come with free 3 to 3 minutes so i had to claim it myself. (my very first contract)
Exclusive offers for existing customers
If you already have a Three contract, with at least a minimum term of 1 month, and you sign up to an additional 12 or 24-month minimum term contract, we’ll automatically add 2000 free Three-to-Three minutes each month to both your existing and new Three accounts. If the additional contract is purchased online via Three.co.uk, you’ll just need to call us on 333 for us to add your 2000 free Three-to-Three minutes a month to your original Three account.
This offer is also available to members of your household (i.e. those with the same postal address as you).