No refund for pre-booked seats

My Pre-booked seats were changed 10min before departure on the 2nd of Oct 2018. After numerous emails and requests, this was the email Mr. Thuli Twala-Mdaka send me on 11 November 2018: "I can request a refund for the unused seats or offer you a total credit of R700 into a Travel Bank account as a gesture of Goodwill. The kulula.com travelbank can be used to book both kulula.com and British Airways flights on the kulula.com website. Should you opt for travelbank, kindly revert with your existing travelbank account if you have one, or you can provide date of birth so I can create an account. I fully understand your disappointment on this occasion, please accept our apologies."

Up untill today 29 Nov, I haven't heard of Mr. Thuli Twala-Mdaka. He offered me a refund, but that was just empty promises. This is unacceptable!!!!!