The contract could be suspended for a variety of reasons such as the job may have violated Upworks' TOS or there might be something wrong with the clients account. You might want to get in contact with the client concerning this. If your job was an hourly job, and you used tracker and made notations on the screen shots it took, then you'll get paid by Upwork. If the job was fixed rate, until and/or unless the client fixes whatever is wrong, you may be out of luck.
A suspended contract is not indicative of a scam.
I have had many excellent clients who at one time or another had a suspended contract. It could simply be because a credit card had its date expired, or they were transitioning to a new card or payment method.
re: "How can I reach a human?"
I can assure you that Kathy and myself and every other Forum participant are indeed human.