Question about One X2 - 611180

For a few weeks now I have been desperately trying to enter a warranty case on the customer portal https://insurance.digitec.ch. Unfortunately, this page does not work, it hangs, no matter on which device and with which browser I try: the warranty case cannot be entered. The customer centre, to whom I have reported this error, reacts dismissively and does not help, for whatever reason. However, when I bought the device from Digitec, I also paid for device insurance for 2 years, so I am entitled to this service. Who can recommend a contact option for me that does not go to customer support ? Unfortunately there is no direct point of contact at insurance.digitec.ch ...