You could act like o2:
1. Make it really hard to contact you. Ask your customers to contact you through email, then give out a defunct email address.
2. Or, alternately, give out two correct email addresses and only respond to one.
3. Don’t employ customer service representatives that speak any English.
4. When someone calls and asks if you speak English, say, “Nein!” and hang up on them.
5. Send a form email saying you’ve received my emails and then don’t respond.
6. The next time someone calls and asks if you speak English, tell them to have someone call back that can speak German and hang up on them.
7. Force your customers to figure out the problem themselves so they can tell you what needs to be done.
8. Act really impatient with their limited German and keep interrupting them.
9. Finally acknowledge what needs to be done and take two weeks to do it.
10. End the entire process with a letter patting yourself on the back for your problem solving capabilities and superior customer service.
or, you could emulate ING-DiBa:
1. When someone calls and asks if you speak English, tell them, “One moment please!” and transfer them to someone that does.
2. Solve the problem.
3. Wish them a nice day.
The latter seems a much more preferable process to me, but what do I know, I’m just a consumer and a foreign one at that.