Mitchell is in a difficult position due to being under age. As Cavey said, they are not planning to keep the money, but freezing it for 180 days. Using a lawyer possibly won't get it back much quicker, and you might have spent the equivalent of the balance in the account before you get a result. Trouble is, Paypal have more money and an in-house legal team - you're outgunned from the outset and once the battle lines are drawn, they'll just stall, knowing you are paying by the hour - very hard to win in that manner, and not economically viable unless the $ are so large (10's of thousands) to make it necessary.

The Ombudsman has jurisdiction as it is the Financial Services Ombudsman (not just Banking, but all forms of financial services). The service is free, so opening a case is likely to be way more cost effective, and might prompt a quicker response.