4s now displayed the plug in to itune symbol but i can not do this as we are away and don't have a computer with us

i had my iphone 4s exchanged at the apple shop in uk about 7-10 days ago and after 3 days it just went dead although it was charged it just went black then it came back on about 5 hours later it did this 3 times but today it displayed the plug in to itune symbol but i can not do this as we are away and don't have a computer with us