No response from Deli by Shell

Deli by Shell is running a promotion involving purchasing a pie and coke and then submitting a copy of the till slip via Whatsapp. I was unsuccessfull in uploading my till slip, much to my frustration. No response from Shell to my Facebook DM, nor my tweet, nor any response from B Sokhela @ Shell - the email address provided for the Whatsapp Business address. So HOW DOES ONE CONTACT SHELL SOUTH AFRICA??