DSL internet service is not working for last one month

DSL internet service is not working for last one month. My DSL contract number is DE16465659 and the service is not working since June 02 it works for few mins and then disconnect for few hours and the connection is highly unreliable and almost useless. I have registered this complaint and my complaint number is 6635427 but no action take so far. Every day I spend 2 hours to connect to the helpline number and but unable to find a english supporting officer. this is really very annoying and now my job is impacted with this

I can be reached at +49 172xxx4142 if O2 wish to resolve the problem otherwise I will start finding new provider soon

Telefonnr zum Schutz ausge-xt (VoIP-Droide)