Difficulty contacting Apple support

I have been trying to contact apple support in regards to unauthorized purchases from iTunes Store and every time I hit support it pops up 43 forbidden. The only other site I found was called just answer and they charge for helping you or rather giving advice on what to do. Our young son who is blocked from purchases managed to get our Visa and says he was able to scan our card one time and after that could purchase anything to the tune of 2400.00 dollars. We don’t know how to resolve this issue and get these charges refunded.