note: Even if the dispute is settled out of court in arbitration, I think arbitration would likely be successful based on the available info. Honestly, if you can open a dispute for arbitration that seems cheaper than going to court and it's likely to work, IMHO. Though most likely is that as soon as a human at Facebook actually groks your situation they'll refund it before going to court or arbitration.

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Note that these arbitration clauses aren’t necessarily enforceable and small claims judges can and do exercise a lot of discretion in their judgements.