sigmacellular I was sold a product that wasn't as described Doral Florida

I purchased a phone through sigmacellular on EBay.  They advertised the phone saying it was in excellent condition.  When I received the phone, there was a crack on the screen.  I contacted the company letting them know that their product wasn't as described.  They told me to send it back, so I sent it back for $12.75 ($8.35 for shipping & $4.40 for insurance).  I told them I wanted a replacement.  They received my item back within a few days and said they don't have any more of the phone I was requesting.  There has been no offer to refund the shipping I had to pay out of pocket for the return and now I have to find another vendor to buy a phone from.  The seller could have easily fullfilled their commitment to their customer by fixing the screen and refunding the shipping the consumer paid.