Unit not working

Q:I just purchased 3 Ring alarms from QVC. However one is not working... it goes thru the set up, shows the area for about 5 minutes then it says offline and the batrery is dead. I have charged the batteries so it is green light only, I have two of them batteries that is and I have tried both batteries and they both do the same thing. I beleive the unit i was sent is bad and I would like a replacement please. Thank you My name is: Rickine Kestin