Bargain 4 CellPhones Inc Will not refund deposit, even though all phones were mailed back, documentation of shipping provided to seller Internet

I originally purchased a blackberry cell phone from this company that was defective.  In fact, three of their phones were defective.  I did not want to be without a cell phone, so agreed to put a $120.00 deposit on having a cell phone shipped to replace the defective ones.  I returned all three defective phones to seller, and have shown him FedEx documentation showing in fact they were shipped.  He refuses to refund the deposit!  Is now not answering any attempts to contact him.  I appreciate any help you can offer in collecting my deposit.  I entered into this transaction in good faith.