Lack of response to request

Our Lufthansa flight from Brussels to Frankfurt schedules for 19 July was cancelled. Lufthansa then rebooked us on Brussels Airways to Rome. This flight was delayed . We missed the flight from Rome to Johannesburg on Ethiopian Air . We had to sleep on the floor of the Rome Airport. The next morning, Lufthansa at the Rome ticketing office helped us and we left on Ethiopian Air. We then requested that the difference in price between Economy Express that we had paid for flight between Frankfurt and Johannesburg be paid out to us; we had to fly Economy class on Air Ethiopia. The request was sent to Lufthansa on 22 July 2018 without receiving any response. The request was repeated on 25 July without any response. Our luggage also got lost in the process and we have not heard anything from them. Does Lufthansa value their customers if they do not respond to emails? Marius Nel