Qatar, worst airline to fly with - zero customer care or welfare

The first and the last time using Qatar airways. Made a reservation for our daughter to fly to Kentucky, US. Her connecting flights was cancelled only hours before boarding at OR Tambo. No notifications were sent. Cancellation was done and our daughter's flights were rerouted causing a whole lot of chaos. Arrival times changed and we had to cancel a shuttle that would take her from the airport to her university 1 hour and 30min away. That was not it!!! We are now in a catch 22 where her flight from Dallas to Louisville departs a little over an hour after landing in Dallas from Doha. That now leaves her with only an hour and a bit to get her luggage, go through customs and security!!! So, we phone Qatar airways on *** and an agent called Ajay assisted us. Although he felt sorry and understand the dilemma, he us there is nothing he can do but put a note on her booking confirmation so that our daughter can speak to Qatar customer care at Doha airport when she arrives from JHB. He also noted that we were not alerted about the cancellations and rerouting and told us that usually they do not send notification out so close to boarding..... whaaaat???? When my daughter arrived at Doha airport she went to Qatar airways customer care counter and tried to get assistance from them. The weren't very friendly and forthcoming in trying to assist her. We were on a video call with her while she tried to get assistance. She was told she is on the only flight out to Dallas. They did not try to assist in rerouting her on other flights so that she has enough time for customs and security when she arrives in the US or be in time for her shuttle. The worst experience ever dealing with an airline. They warned us on their website and app that the layover for customs is short however they made all the bookings and the changes but was not willing to assist after they did cancellations and rerouting! Disgusting service from an airline I cannot think has a good rating, causing it is utter nonsense.