Depends on each instance’s rules, based on what you are referring to.

Account ban? (You not being able to access your account at all) Refer to your instance piefed.social’s rules.

Communty ban? (A community within an instance banning your participation) Refer to said community’s rules.

Can’t interact with an instance? (not being able to interact with all communities using the same instance) Said instance might have defeferated with your instance; contact piefed.social’s admins for clarification. Both parties should be in an agreement for them to federate again.