Thanks for the responses. I did indeed complain online but am happy to call also. Was a super disappointing experience. A friend is on the ATL-JNB flight in J tonight so I will ask him about his experience to compare...
Agreed, the food was simply unacceptable in terms of quality and quantity. There were definitely no sandwiches or cheese- there were about 4 bananas that were taken within a few hours post-meal but that was it. Was literally identical to a snack basket on a short regional hop. Totally disappointed- probably a European carrier for me next time, but i'll see how the (much longer) return from JNB-ATL is next week...