Fitbit technical issues???

I love my fitbit, am addicted to my fitbit, and want to start by saying they have so far had GREAT customer service, but the fitbit itself seems to not be very durable, or I am the unluckiest person in the world.

My first fitbit seemed to have a bad battery, it died after about 12 hours use. They sent a new one and the replacement worked great for a few weeks, but now keeps shorting out. It will go black and stop recording steps, but if I plug it into my base station it comes back to life(it is frustrating because when it happens and I am away from home can't reset it all day- this happened to me at work today, and I'm looking at losing 2 miles walked and 12 miles biked plus inner office steps taken ).

At first it seemed to happen mostly when I was exercising so I started clipping it to my shirt instead of my bra if I was planning to sweat, but now it is happening quite often, even if I am not working out(and my husband has commented on the new "fashionable" accessory I keep wearing on my shirt collar). They have promised to send out a replacement, but have NOT given me any idea as to why this is happening, and I am afraid it is something I am doing wrong, and will happen to the new unit too.

Anyone had a similar experience?? I wish I could figure out what the issue is. I don't want to keep killing fitbits even if they do keep replacing them!