my iphone 5 charger has to be wrapped around the phone and not touched for it to charge. WHY?

have never dropped my phone. it has been well looked after but i am having trouble getting it to charge. i have to wrap the charger cord around my phone to get it to charge and cant touch or move the phone other wise it doesnt charge. i have tried many different iphone 5 charger cords and wall bits but it constantly has trouble charging. why? and what needs to be done to fix this. my partner also has this problem.