Disgusting conduct by the company

I am absolutely shocked by the service and communication I got from a company that is supposed to be so reputable. I rented a vehicle in November. Between Jan and Feb my bank account was debited about R6 000 in excess fees. I was never invoiced. I sent several emails requesting an invoice or a statement or some form of breakdown for the additional charges. I never got a response. A week back (30 March) I received a letter of demand telling me about damages immediately due on the November rental. Documents sent to me were manipulated in a way so obvious that every Tom, **** and Harry can see the manipulation. Now that I am seeing the comments on this page- I am actually so shocked- I would have never expected such from such a big company!