Chime pro not connecting to WiFi

I've just bought a doorbell 3 and a chime pro, because I couldn't connect the original doorbell and original chimes I spent several hours this afternoon connecting the new bell and chimes. The chimes failed to connect with a very strong WiFi signal 5 feet away from the router. The new bell works 15 feet away a smart TV connects to the router OK despite being in another room divided by a brick wall and 20 feet away. I tried the chime 12 inches from the router. I feel I have wasted my money. How do I get this rubbish to work??? I have to set up a smartphone and tablet to be able to use the doorbell. A sad costly experience RING - how do I get this to work ????????? I want my money back