Why is my iPhone 5 still showing charging yet no lead is attached?

I recently bought a " grade A ' as I understood non recon iphone . ( less than 3 months ) from a shop on eBay . I am using the cable it came with. Tbf it look like a genuine . I have an iPhone 4 new from day 1 ( still mint but no iOS 8 ) any way I was speaking to my daughter and charging at the same time and my screen went to the charge pic . And I lost her . I've tried the on/off and home at the same time several times . Nothing ! It remains . But won't turn off . It's now the longest iPhone charge in history ! . Can you shed some light please . To this troubled apple
Kind regards joanne
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What is a "grade A" non recon iPhone? Anyway, I can only assume you had a spike during the charge that could have caused the issue you are having. How long did you hold both the home and power buttons in an attempt to reboot the device? How long did you hold the power button in an attempt to turn it off? It's possible that restoring your "settings" could help, but I can't say that it will for certain, but heck, it's worth a try. You can always take it to the closest Apple Store to have them run some tests for you.