Warning if you are travelling with United Airlines

My son is based at university in the USA so frequently travels between USA and South Africa. When he departed back to USA in August on UA2223 from CT International Airport he had any amount of 350 dollars ****** from his wallet by a security person checking those boarding the flight. I have taken this up with United Airlines but they are not really interested in getting involved. ACSA security have the person on camera digging in the backpack to ***** the money but refuse to release the footage to me. It is obviously very concerning that personnel that are meant to protect United Airlines clients are dishonest and are getting away with it due to the lack of interest of United Airlines to get involved with sorting out this issue of theft. I tried to lay a charge with SAPS but they say it is out of their jurisdiction. So be extra aware if you travel with United when their security search your bags etc as they could remove items knowing that United and SAPS are not really interested in rectifying the situation. Will be traveling with Delta in the future to avoid such instances.