I have switched all my service accounts to the Won heaters. I use them in all my tanks here. I haven't had any problems with them so far. Nothing is infallable though and you might have gotten a bad one. I wouldn't buy anything else. Your Won heater came with a 1 year warranty anyway. If whomever sold you the heater will not stand behind it, I will. Send it to me and I'll replace it and get it covered under warranty. Include a copy of the invoice if you have it.
Life is not measured by the number of breaths we take, but by the moments that take our breath away.