I'm puzzled by this. It seems obvious that Robin committed some kind of fraud against Upwork by using someone else's credit card. Upwork should be asking him to

I'm puzzled by this. It seems obvious that Robin committed some kind of fraud against Upwork by using someone else's credit card. Upwork should be asking him to pay his debt, not OP who (says he) didn't breach his contract. Is it Upwork becoming big enough that it can start to bully people around and make extortionate demands knowing that it will be hard to refuse ?