Inadequate compensation for delayed and cancelled long haul flights

I recently had two bad experiences with Delta Airlines on their long haul flight between SA and USA. Our outbound flight from CPT to ATL was diverted to Miami "to refuel" and delayed 6+ hours. Our return flight from ATL to JNB was delayed then cancelled after midnight. Total chaos. We ultimately had to waste THREE days in Atlanta, most of which was spent at the airport looking for "lost" checked luggage that was supposed to accompany us but mysteriously flew without us despite the "strict" rules against unaccompanied baggage. Delta is simply not interested in reimbursing costs incurred over and above the hotels and measly meal vouchers that they provide. So disappointing. The story is so much longer including poor service and a general lack of concern.