Iphone 4 has blown up please help Iphone 4 has blown up please help

Hi i have had my iphone 4 for 18 months i have plugged it into charge and left it as i usually do, there was a huge bang and a flash and the plug and phone flew across the room. th eplug had snapped in half and was black.

my phone is not responding to anything it just keeps on vibrating and is that hot i can not touch it. im with vodafone i rang them and they said try and put it outside to cool it down and switch it off.

funny answer considering i told him it had just blown up! im really worried and dont know what else to do or who to contact. can anyone help me? and will my phone be insured as i dont have insurance on my phone at all they wanted an extra £20.00 a months for insurance! i could buy a new phone for that!

please help any feedback is welcome. thanks

Sam