Terrible product

I purchased a ring doorbell2 on July 5th. It works fine for 2-3 weeks. But the battery was dead within 2 weeks. I had to charge it a couple time. So I decided to hardwire it with a transformer. It stays “hard wired” for 1 week. Today it says battery is very low even it is hardwired. So I took it off from my door frame and use a usb cable to charge. But it does not charge. I tried many different mini usb cable and usb power supplies. None of them work. The battery does to charge up. And it passed 30 days so I cannot return it. What a junk product.