DSL internet down

My internet has been down for over 24 hours now, saying no DSL connection. Christinenstrasse, Berlin. Router unplugged, restarted, all cables re-connected, nothing. The router's troubleshooting sheet suggests that the incoming DSL connection is broken. Tried calling o2, but they only connect you to live assistance if you are seeking a new contract - for technical issues they point to their website. Their chatbot there says: "I cannot assist you in english, sorry. Please contact our customer service at 089 - 78 79 79 40 0 (costs are depending on your regulation for german landline calls).