VERY DISAPPOINTING SERVICE FROM KULULA.COM

I am very disappointed in the service from Kulula. I spent a fortune on airtime trying to reach their Call Center at the number provided and after 6 attempts and holding on for at least 15 minutes on each call, there was no answer from any agent. I logged two requests on their website and to date, no response has been received. Can someone at Kulula please assist me to cancel my booking number ENALYB in the name of MARJORIE DAVIS and EUTRICIA MVELE and please furnish me with a voucher to use on another flight at a later stage.