Bad service and dry Double big Mac meal

Today I bought Double big Mac at MacDonald cape town station . It was very dry , no sauce nothing . I asked the lady at the till to put on sauce , she say I must add another money for sauce 😔. I asked for a refund because I can't but a double big Mac for R93 , dry one . She says it's impossible. I am very disappointed 😞☹️ with MacDonald cape town station and will never ever set my foot from there again