Travelstart messes up my trip

I booked to fly to Cape Town on Travelstart, big mistake (ZA ********** 7). You have to download their cellphone App and then check in beforehand. This is not stressed anywhere. I tried to do this, got a check in number which I wrote down (JPOJSI), but the process did not concluded. This means I did not get an email with my boarding pass. When I arrived at Lanseria for the flight they refused to board me because I did not have the boarding pass on my phone. Their terminals close 40min before the flight, and they were totally adamant, but that is another story. Suffice to say that I had to abandon my booking and LOOSE it, and buy another ticket to my destination. I have written to them lodging a complaint and asking for a refund but they have only sent a canned reply so far. I will NOT EVER book through them again.