KPN ONT converter ontbreekt bij router: monteur aanvragen zonder bellen

I have received the package with the router. I am missing the ONT converter to connect it. I only have a foreign number and cannot reach the customer service number. If I try the  +31 6 1200 1200 it jsust hangs up on me. I need to schedule a technician to come and connect it. How can I schedule a visit without having to call the number? Is there anywhere I can write? Or go to a shop?