Bests & Worsts Reviews from Amazon

This is a revision of my previous review, and a profound downgrading. I ordered this product about six weeks ago. I set it up and programmed it without incident. The system worked perfectly for a month or so. But just after the return window closed, the transmitted audio stopped working, as if the whole system were on mute. The party on the other end of the conversation could be heard perfectly, but they could not hear me. I asked for help from V-Tech through the Amazon.com arbitration system, and was promised a response within 48 hours. That did not happen: I got no contact from customer service, no suggestions about a possible fix, no apology for my inconvenience, no offer of a replacement or a refund. Crickets. Right now, it looks like I'm stuck with a $60+ system that doesn't work. Nor, apparently, does the amazon.com/feedback system. This long-time Prime customer has been a satisfied customer up to now; but I'm extremely disappointed now.