Regardless of the reason your account was restricted, the only way to get out of this restriction zone is by contacting bet365's customer support. Even if you have no idea why your account has been restricted, you should still contact customer support to get an idea so you can open it back.

You can self-exclude your account in the Gambling Controls section in the Account Menu by choosing Self-Exclusion. Alternatively you can contact our customer care team for assistance and further information.