How do I file a PayPal dispute?

If you have a PayPal account (and used it to pay)

1. Log in to your PayPal account.
2. Click Resolution Center.
3. Click Report a Problem.
4. Select the reason click Continue, then follow the instructions.

Here are PayPal's instructions if you need anymore help with this

If you paid on PayPal, but with their guest checkout method: 

1. Look up your Unique Transaction ID. Click here if you aren't sure where to find it.
2. Call up PayPal and tell them you want to file a dispute.

PayPal’s Toll Free Number is 1-888-221-1161  and PayPal Customer Service representatives are available from 4:00 AM PT to 10:00 PM PT, Monday through Friday and 6:00 AM PT to 8:00 PM PT, Saturday and Sunday. 

Once you have filed a dispute, you must escalate it to a claim in order to receive a refund. You have 20 days after filing the dispute to escalate it to a claim.

Note also, if you paid through PayPal but funded your payment with a credit card, you have the option of calling up the bank for your credit card and filing a dispute through them.