Requesting a refund is different from a charge-back via PayPal. Working with any contractor be it an agency or a freelancer there is always a risk you wont be happy.
The correct way of dealing with it is to find an agreement you can both deal with. Not use shitty Paypal tactics to reverse the charge.
If you go for dinner and don't enjoy the food, you do not pay, leave and then call Amex and tell them your card was stolen.