Sam Anupam Ghera's son Nikhil thought he was using up game points every time he 'improved' his characters while playing Call of Duty and Fifa.
However, with each click he was actually purchasing an online currency, which was draining money from his dad's account, the Daily Mail reported.
Now Sam, from Wolverhampton in the West Midlands, wants to warn parents of the hidden costs lurking behind games consoles after he was left with a sky-high credit card bill.
Sam, 48, had allowed Nikhil register his credit card details to cover the 5.99 pounds monthly subscription fee so he could play X-Box Live with classmates online.
However, unbeknown to Sam, his card details were stored in the machine and his son was able to buy "Microsoft Points" -- an online currency which allows players to unlock new features in their favourite games --without having to enter a password.
The youngster thought he had earned the points for scoring goals and killing villains and he used these to add extra weapons for his soldier in hit game Call of Duty and players in football game Fifa.
Between December and June this year Nikhil spent a wallet-busting 1,150 pounds.
In one marathon gaming session Nikhil spent 100 pounds in a single day on weapons and extra features after playing Call of Duty with his online friends.
Sam only realised what was happening when he tried with use his card to withdraw some cash, and was told he had insufficient funds.
He was horrified when he realised his own son was responsible for the credit card bill.
Sam has now lodged a complaint with the computer giant Microsoft, which owns X-Box Live, and is demanding the company makes its charging policy clearer for parents.
