Peaceful Sleep No Longer A Good Product

It use to work very well, lately the unit for the pad doesnt work, out of four units that I purchased it isnt making hot anymore and even if it does the pad isnt working to keep the Mosquitos away. I have puchased three boxes of pads and they not working, Like I said years ago it worked perfectly I dont know what has happened to the Product. I have sent them three emails with no response.