Owning a credit card is a big responsibility, and it definitely shouldn't fall into the hands of a Roblox-obsessed preteen. One dad found that out the hard way, as he shared with the r/mildlyinfuriating Reddit community. At first, he was just sharing a long receipt of micro transactions that his son had made at the App Store . Spend a dollar here and twenty dollars there and it can really add up fast! The kiddo thought he had a gift card to spend, but once the gift card ran out, he was able to…