Battery discharge problems

[Chatterbox]

Help! I'm exasperated, I'm currently on my 4th iPhone 4s since December 21st, due to battery discharge problems. I had my initial phone in June & was very happy with it until early December when the battery discharge problems started, they sent what I thought was a new one but they are refurbed, the problem occured again. I spent hours on the phone with a senior iOS advisor & did resets which they thought had resolved it but it hadn't. So they sent another refurb one & it happened again, to ensure it wasn't a charger problem I bought a new apple one but the problem was exactly the same, fully charged at night, by morning with no use it would be dead. On Monday I received a brand new one & it was great until last night when I restored via iCloud & downloaded a few apps by this morning it was dead. The phone wouldn't recharge via a USB on my computer, but it did when plugged in to the mains, as soon as it was unplugged the battery started a rapid discharge! Anyone with any clues??? When it's discharging it gets very hot. I've booked an appt in the apple store as I am almost too embarrassed to tell them it's happening again, so I want them to see it for themselves. I have to say that on the whole apple have been amazing throughout, I have had direct contact with an advisor so haven't had to repeatedly tell my story. Also I should mention that all my chargers are fine with my iPad & my husbands iPhone 3.

Any comments/ advice very gratefully received, thanks for taking the time to read this waffle!