UBER CHARGING FOR UBER BLACK WHEN UBER X IS USED

Hi,<br> <br> I have written to Uber with no response.<br> <br> I use Uber quite frequently and recently when I am requesting a pick up, it continually says that an Uber X vehicle is not available. I don't mind this on an odd occasion, but it is ALL the time and at different times during the day. I requested a pick up on Thursday 10th march and had to request an Uber Black vehicle, no Uber X available. The car arrived - a tatty Toyota corolla. I was in evening dress and I had to get into a car that was filthy and had soil and other clay marks on the back seat. This is unacceptable that a vehicle is used in this condition, but my biggest issue is that I was charged for an Uber Black vehicle! This was not an Uber black vehicle and I was charged double the rate. I want my money back, not a credit against Uber as I am seriously thinking of not using them ever again.