Maybe PayPal has to many users and they are not able to support all the cases. But I do agree with g36, I will not dare using PayPal for transaction money over 50$. Maybe can use Western Union. It might be safer.
You can try to get your funds by mailing you higher authorities and making repeated calls to Paypal. You can use Skype to make free calls to Paypal tool free number. Google out for higher authorities number and you can find president of Paypal on Facebook too... just message him.. You might be feeling it wont help but it surely helps... as he personally forwards the messages to complaint department head.
I don't get it. Why there are so many people who try to cheat others for their own benefit. $200 is still $200 and for sure you worked hard in order to build that site of yours. Try to contact paypal again. Goodluck!
The problem is often not with PayPal, but the buyer. Usually, when such thing happens, it turns out that someone paid you using stolen credit card or paypal account. In such case, PayPal gets chargeback request from credit card issuer. Then, PayPal has to refund the payment. As PayPal is not a charity, they are not going to pay out of their pockets, so they will chargeback the seller.