Travelstart no direct contact information

Travelstart. You pay R650 to move or change your flight date. There is no contact no that you can call for assistance. They have a computer operated Whattsapp that never comes back to you. I tried changing my date after many e mails an Whattsapps. They keep saying after 24 hours you will be assisted. This never happens. Very poor and bad company and unprefessional