Uber ****ming its users?

Back in April, I requested an Uber. The trip was to be paid in cash. At the end of the trip, the driver showed me a price on his end that was different than the one showed on mine, a discrepancy I only noticed after paying. I raised the issue with Uber which they had resolved but giving me a promo code that said to be valid until 2024. So last Saturday, remembering that I still had a promo code from Uber, I decided to use for the trip, just to find out that Uber gave me an invalid one.

So I’ve been explaining to them since Saturday that they game me a bogus promo code and I needed to be given a valid one. All they’re telling me is that the code should be app**** before the trip, which I had done but it kept on saying that it was invalid code. Now they are all acting clueless when all I was is for a working promo code which was meant to be a resolution for a mistake that had happened on their end.