Today I tried to hook up an extender to my Deco M4R (V2). I bought an RE300. My old ones were M3W's.

None of them work. They will not connect to the main unit. I tried to reset everything and realized that I was not even hooked up to the Deco system. I must not have understood how to connect it when I bought it and I suspect that this entire time I've been getting my wifi connection off of my modem. So I downloaded all the apps and called customer service. Got the main unit connected. But none of the extenders will connect. I have been trying to get this working for about 3 hours and I'm about to shove these damn things down the garbage disposal. 

The M3W's get a white power light but a flashing red light on the internet. 

The RE300 only get's the white power light.

This process has been so complicated and frustrating that I'm not sure this is worth it. Please help.