IPHONE 5 will not charge

Hey guys,

This is my third iPhone 5 since late September when I got it on release day.,

My first one was overheating

My second was a faulty lock button

And now my third, it will not charge and sometimes will not turn on.. Like technically it would still be 'on' but when I press the lock or home button it will stay black.. Even when I flick the cribbage switch it will not do anything.. So I wait 2/3 minuets and it pops back to life..

The charging thing is a recent one.. It just sits on the percent that it was on and then slowly decreases. To 0%. I am seriously doubting iphone 5.. I'd honestly just go back to my old 4 if there is going to be that many problems with these ones..

Quite upset that my phone won't charge.. I run everything off it..

Please help!!