I am not a lawyer, but I think Terms of Service only apply if you want to... continue receiving/using the service. So even if it the TOS does have a forced arbitration clause and OP takes FB to court instead, I believe that would just mean FB could then say "You broke the TOS so we're going to suspend your account" which they've already done and so there is no incentive for OP to abide by it unless they care/expect to be able to do further business with FB in the future.

(If someone with experience with these things can provide additional clarification or correction, I'd appreciate it!)