Paypal stole my payment and there is no control body to go to

Can anyone help me. I need to know what to do when the Paypal Service which is supposed to be a secure online 3rd party payment service took my money, but never put it through to the vendor. So they sit with my money and when I contacted them I got a reply that there is nothing irregular with this transaction. To who does one go when a supposedly trusted vendor like PayPal does this?