Ask a german speaking friend to call this number from your flat.

Tel:0800 52 51 37 8 Kostenfrei. Rufe diese kostenfreie Service-Rufnummer bitte möglichst von deinem Mobiltelefon aus an, da zur Problembehebung u. U. der Router neu gestartet werden muss und dadurch Anrufe vom Festnetz unterbrochen werden.

@aqib0080 you can switch the service app to an English menu. 
https://hilfe.o2online.de/english-o2-community-broadband-dsl-70/how-to-create-a-technical-error-ticket-for-v-dsl-line-at-o2-510083

Hello @aqib0080 and welcome to our o2 community :-)

If the DSL connection is not working as it should the o2 my Service App is one possibility to help loacting the reason for this and may in same cases even help fixing this issue.

As @Joe Doe stated you also have the possibilty to change the language of the app to english.

If it is necessary to contact our technical DSL departement and you don’t speak any german at all I recommend to call with a friend of yours who speaks german since we can not promise that you will reach an english speaking agent.

Regards,

Lars