I'm going to return it today and I think I'll wait for the 6s. The 5s was a very stable device, I just didn't like the design or weight at the time.
I'm still wishing they'd make a 6c this next year. I'm hopefull, not optimistic however.
I would exchange it. I've handled enough of them that I can assure you what you got is an anomaly.
I can't even use my 5S anymore. Its seems unreadable and slow to me now lol.
I wonder if you got someone else's return unit?
Don't know buy the guy didn't act surprised when he saw me come in to return it. It's okay, I really wanted to keep my 5c anyways. It's not like there is anything wrong with it. Traded in my other 5c and older iPad. Saved almost $300 on this new iPad mini 3 64GB in space gray.