Ubereats driver stole money

I ordered on Ubereats a Nandos meal, I said I would pay cash on the app. I had R100 cash on me and the meal was R88. When the driver came he said he didn't have change so I went back inside the house to see if I could break the notes and I came back out with R90 and paid him. I got an email from ubereats saying I didn't pay when I did pay.