Carstereoneeds not responding to emails after sending in my stereo for warranty Murrieta California

I ordered a car stereo on ebay from ebay user stereo-needs (Carstereoneeds) in April of 2013. Sent it back for warranty after about 3 months, with no problem, they sent me a replacement right away. Good service I thought, pretty legit. Well this summer the unit started acting up again, volume knob stopped working and the remote was not working either, yes I replaced the battery, twice to make sure. I went through the email thing with them through ebay and every thing was going great, good communication and Liz sounded very help full.

     After all the emailing, she sent me the mailing address and was told to include a check or money order for $20 to cover return shipping, so I sent a money order and had a tracking # (9114999944238095472106 if you want to check) delivered 9/11/2014. I have heard nothing, I had to contact ebay and tell them the situation and get contact info for them. I sent an email and called their phone # (951 200 4884) but that only has a recording that directs you to an email address. I can't believe that after all the good email communication and the no hassle 1st replacement that this has happened. I wish I would have come across this site before I ordered. The only thing is that the money order hasn't been cashed yet but not sure it is worth trying to get a refund being it cost $15 to start refund process. SCREWED... I will try and go through Paypal and see if they can do anything. Other than that I am not sure what to do.