Is there any higher authority which i ca report paypal to or file a claim against them,

[Lanreslim2K5]

Paypal is holding onto my money about 2500$. Exactly similar cases were refunded and they redeclined me half of the money which was very obvious. 

Refunds to my bank account did not show up and its hidden somewere in paypal transaction. Is there any way i can sue paypal or report them to a a higher authority