Keine Internet Verbindung! >2 Wochen!

Sorry for English, but my German is not so good. The problem is as following. At some point I got problems with WiFi connections between router and Laptop. From time to time the connection was lost and I had to reset WiFi on router. Then I decided that the problem comes from router settings and one needs to reset it to a factory settings. I clicked on "Neu start(?)" button in its corresponding settings. After that the INFO LED became red (the other LEDs are green, including DSL). In the manual it is said that one has to reenter PIN again. However, when I turned the phone on, the lady said that there is no connection and one has to contact O2 for support. The O2 has made an appointment with technician (about one to wait for him). The technician said that there is no problem on his site (die Anschluss ist OK). The O2 didn't do anything after that, but made a new appointment with technician, saying that in the previous visit he did not make a full test or whatever he has to do. Another weak of waiting!!! And the new technician says that everything is OK on his site!!! So, why don' O2 checks server settings or whatever on their site??? Is it a problem to check server settings first before sending technician to me? I am getting crasy already! The situation is so stupid! I am thinking to break the contract with O2, since they are not able to do their simple service!