None responsive to Client Queries

I booked a Trip with Uber on the 27th of June, which they Deducted from my Account. Then the next day they charged my Account for the same amount again. I then send through a query which I couldn't complete on their system because the automatic frequently questions didn't cater to my query. I then tried to reach out to their Support with no joy. With them charging my Account for a whole week with an extra charge that exceeded the fees in my Account I am now in a negative & I cannot raise my query with them. Please can you advise on what I should do now?