Accused of *****ing

Recently I have had such a bad experience with UberEats after always being happy with their service. For the past couple of orders, I have always paid by card, but my most recent purchase was paid with cash. My order came to under R150 and I specifically told the driver to have R30 change. When he arrived, I gave him 2 R100 notes, and he gave my change. I enjoyed my food, and when I checked my emails, I saw an email from UberEats saying that I did not pay for my recent meal. This obviously shocked me as I'm sure the driver would have said something immediately if it was not correct. Immediately I went onto the app to ask them how this was possible. All I got was a generic response to say that my arrears was cleared as my account has always been in good standing. Nowhere did they ask me what happened, or explain how this could have been. Instead, the implication was that I did not pay. The next day I sent another message asking how it was possible that I did not pay and saying that maybe they should check with their driver instead of accusing me of having food without paying for it. Again, i got the same generic response. This infuriated me. In fact, it still does. I would like to get to the bottom of this but it seems as If UberEats has decided that I am the guilty party and they won't even bother to investigate it or to ask me my side. I am absolutely appalled by their service, so much so that I no longer want to make use of their services.