You can request the lifting of a suspension in Swiss casinos at any time. To do so, you will need to make a written request to the casino that imposed the gambling suspension, and attend a personal consultation.
If you can prove that the reason for the gambling suspension no longer applies, the suspension will be lifted (Art. 81 of the Swiss Gambling Act). Voluntary gambling suspensions can only be lifted after a minimum of three months (Art. 84 of the Swiss Gambling Ordinance).
If you had the suspension imposed in a casino that has since ceased to operate, you can contact a casino of your choice. They will be able to advise you on how to proceed.