Bad customer service

I ordered a Big Mac on promo and 6 spicy nuggets but instead I received the spicy Cajun meal. I contacted customer care and they said they will refund me. Guess what they refund me R1.60 since they say the spicy Cajun meal is more than the Big Mac.I contacted them again and then they said they will refund me for the nuggets as well. I don’t understand how this mistake is my problem because they the ones who messed up my order!!!! . Why won’t they refund me the full amount. Don’t make the mistake from ordering scoots again .. rather user Mr Delivery or Uber Eats at least they don’t mess up your orders !!!!!!!!