My iphone went dead and now won't charge up?

My iphone 4 went dead a few nights a go so I plugged it in to charge and it showed the charging icon on the screen but wouldn't go past red after being charged for a full day, and now it has changed to flashing the apple icon constantly when plugged in charge

I have tried to put it in recovery mode on itunes however it didn't work

It's the battery: it's dead. You either have it replaced or get a new phone. It happened to me 3 weeks ago and I got a new iphone5:)

For this answer I would like to tell that you consult to a mobile company from where you purchased the mobile as they will only guide you in this matter.
http://rokform.eu/en/products/screen-protectors/