Phone won't charge

My little sister got the Ulefone for Christmas. It's been a cracking little bit of kit thus far, but today it died and now won't charge at all. We've tried several different chargers and sockets, so I assume it's a fault with the phone's charger port. This has never happened before, and she says she didn't do anything out of the ordinary with it. Any help or suggestions at all would be much appreciated!