iPhone 4s Problem

[JamesU]

Hi Guys,

Because my Samsung S4 was dropped and the screen is now buggered, i've had an iPhone 4s from a friend to tie me over until my contract renews in a couple of months.

Everything on the phone seems ok apart from calls...

I cannot hear the person on the other end of the phone, and they cannot hear me. When i adjust the volume it doesn't say (headphones) and if i put them on loudspeaker the problem is the same.

I've tried to plug headphones in and it doesn't even recognise that they're there so will continue to play music through the phone speakers.

I've hooked it up to my car bluetooth and even then i cannot hear the other person or they hear me.

If i use Siri, then it recognises my voice fine...so i'm a bit baffled.

I've restored the phone twice, and upgraded to the latest iOS firmware, but i have no idea really what to do next!?

Does anyone have any ideas?

Thanks,