How do I get ebay involved in a refund when the supplier continues to say they will replace it and I

[daytime24-7]

How do I get ebay involved in a refund when the supplier continues to say they will replace it and I wait and wait until the only answer on ebay is that the time has expired and it wont allow me to make a claim for a refund? 

[kopenhagen5]

Log into PayPal and first sign up for the free returns then open a case in their resolution centre for INAD.