Uber attempting to take money from my banking account

I have had Uber try to take money off my banking account numerous times already. I contacted my bank and they say my that I should stop my card and be issued with a new one which will cost me R70 I don't have!!! I have tried, unsuccessfully to get hold of Uber to put a stop to this! Each time they try to take money off my account, i get charged a fee which has not put me into a minus on my banking account. Uber, best you sort this out immediately otherwise I will lodge a ***** case against yourselves. And please contact me via my email address as I am not available on my phone as you have also taken all my money for airtime!!!!!!!! (***)