Overbiling driver

Debonairs Woodstock, Cape Town delivery guy just rubbed me. I ordered 2 pizza's to the value of R340 and he charged me R440. I only realized now when taking my phone that he charged me R440 instead of R340. Even worse he almost ripped the total on the slip which makes me think this is intentional. I have been trying to call them, it's been back and fourth of wasting my airtime and time. I am so unhappy and disappointed with Debonairs