Hello adande1937
When you have signed the GA contract, you agreed to the contractual terms; one of it was the minimum term of six months. You should have considered the terms before signing; alternatively, there would have been the 1-month GA Travel Card.
Whether SBB is willing to cancel the contract within the 6 months is to be decided by SBB, we are unable to help you through this platform.
Please contact SBB: 0848 44 66 88 (CHF 0.08/Min, waiting times are possible).
Kind regards,
Roland