Ticket cancelled in error forcing me to buy a new ticket at high cost

I was on a multi trip flight (CPT-NBO-KIGALI-NBO-CPT) and needed to amend one of the legs. I was advised that it couldnt be changed as I had checked in already so would need to ask for a refund and book it myself which I duly did as follows:

"Thank you for the confirmation and grateful if you can apply for a refund for the NBO – Kigali leg this evening. I have gone ahead and booked the new leg as suggested - ZA ********** 6."

Turning up at the Kigali airport to return to Nairobi, I found after about an hour of to and fro (in fact Air Rwanda initially allowed me to check in) that Travelstart had in fact suspended the ticket for my whole journey and I was forced to buy a new one with minutes to spare.

At this stage I don't know if I have a return flight to Cape Town on Saturday the 2nd September or not! Dale, please sort out my return ticket as we leave the next day to visit a sick nephew in Upington!