Miband 1 no longer connects or pairs... is it gone?

I've had a series of bad behaviors from my Miband 1, beginning a few weeks ago.

1. With the call nofication enabled I received a call but the band would not stop vibrating. I had to let it continue until it ran out of battery.
2. A few weeks later, when plugging in I got vibration instead of charging. Let the battery die for 2 days and it finally started charging again.
3. This week it takes much longer than usual to sync with phone. Used to be 5 seconds, now it takes about 60 seconds.
4. This morning it would no longer connect. When I plugged it in to charge it started vibrating, but when I uplugged and replugged it went to nomral charging. Still would not connect to the phone. After that I tried to unpair and repair, but the band does not respond in any way when I put the app into pairing mode.

I suspect it's getting close to its demise, but I wonder if you guys can suggest a fix that might revive it.

Many thanks.