cancel flex contract

Hello, 

I would like to cancel my O² Free Unlimited Flex mobile phone contract. I used it to have internet but now as I have a O² DSL contract at home I don’t need my Flex phone contract anymore. I saw that I need to call a phone number to confirm my cancelation but as I don’t speak german and as each time O² calls me it’s impossible to chat because the phone caller doesn’t speak english, how can I do that? It there a mail service where I can send a mail with the help of google translate or is there an english hotline to do that ?

Thanks in advance