Ebay seller with vw/skoda radio units for sale

This thread isn't about saying all his radios are faulty but more don't be like me and get sucked in by someone who is really good when you make enquiries re columbus rns510 and ultimately bought a reconditioned unit off him with a years warranty as long as security seal in place.My dealings with him....called Eric...were very good .The unit came and for 6 months has worked fine until now power fluctuates. .Went into ebay to message him to find his ID did not exist anymore and it was now alf2020...After sending at least 4 messages I finally got him to reply He said he wasn't Eric but strange how user ID had automatically changed to new one and my review at time of purchase is amongst his listing..Basically he is not going to honour the warranty as I have had the radio for in his words...half a year..all his current listings are exactly the same as when I bought.Again this isn't me saying stay away...just be careful what's on offer and make your own mind up.I have probably been unlucky with the one I bought....which I am trying to find someone to fix for me...