No service ethic

i booked economy class flights from Cape Town to Canada and then decided to upgrade. I e-mailed and had a return mail asking for my phone number. That was the end of all contact. I e-mailed again and again, without any response, so tried phoning. It took at least twenty attempts to get someone to answer, and that only because I selected one of the options although it wasn't an option that app**** to my query. The person who answered said she would ask a colleague to cal me back. That was it. End of `customer service'.