Harmful Business Practice

I recently ordered from Uber eats, it was a buy one get one special. I ordered 2 for R120. Only 1 was delivered. After lodging a dispute they refunded me R30. I disputed this as they should have refunded me the full R60. Their response was that the promo code didn’t go through. I again disputed this because o paid R60 for the food that was not delivered. Their response was to shut me down by saying they resolved the dispute and closed all communication on the issue. This is at best ***** abs at least a harmful business practice