Tilly Davies' usual bill was £30 a month, but since upgrading her handset to an iPhone four months a go, her bill escalated by epic proportions.
Her outraged dad, Kurt, 46, branded the bill an "absolute joke" and is refusing to settle the amount with the phone provider, Orange.
He told the Mirror: "All Orange has to do is look at Tilly's bill history and see that it is only £30 per month."
The dad-of-five from Leigh-on-Sea, Essex, added: "The massive bills came in after she upgraded. Orange told me it's down to 'data usage' but she hasn't done anything differently to before."
Orange say that are "sorry" that Tilly has found herself in "this situation" and that they are investigating.
Good grief! £7,000!
Have your kids ever run-up epic bills on their mobiles?