I would get it exchanged. Something doesn't seem right.Does the LED light on yours ever flash? I purchased two for my bed stand (and my wife’s) and every time I lay the phone on the charger it starts charging perfectly.
But sometimes in the middle of the night when I wake up to go to the restroom I notice one of the lights is flashing. I pick the phone up (place it back down) and it starts working perfectly again with a solid LED light.
According to Mophie’s website it starts flashing once it detects a metal/foreign object? But I obviously don’t have a metal foreign object on there so I’m a bit perplexed.
I have the Belkin and it's been rock solid. Steady green light all night.
As a comparison, I also bought the Choetech Circle Qi - it's around $12 and seems to work just as well. The only thing is it will not do 7.5W charging, only the standard 5W. So if you use a 12W wall power supply to compensate for the losses, you'll get about the same charge rate as the Apple-supplied 5W charger, but no faster. The Belkin will do 7.5W charging (once Apple updates the software).