Step 1: Contact the Bet365 call centre and formally ask for account activation. Note that Bet365 can treat this request only if your self-exclusion period has ended. Step 2: Once the betting operator has handled your request, you'll get a confirmation email. Click on the confirm button to activate your account.
If you want to stop playing for other reasons, please consider a Time-Out or using Account Closure. What happens when you self-exclude? During a period of Self-Exclusion you will not be able to use your account for betting and gaming, although you will still be able to login and withdraw any remaining balance.