Unable to call KPN to terminate my contract

Hello,

I would like to ask if there are any other possibilities to terminate my contract as I am now abroad on holidays and I am unable to visit any customer service. I was trying to call KPN number 0800-0402, but it keeps me disconnecting after 1 second (I have lebara mobile sim and I can call all of the numbers, so this is not an issue).

I have a contract that I can terminate monthly. I moved to a new house 30.11.2023, but my landlord said after I moved in that I can use his internet and there is no need to pay extra costs for my own internet. I also have an internet installer appointment which I've done before my move which I can't cancel now and it's scheduled on 15th December.

How can I terminate my contract and cancel appointment?

Please help 🙏