Complaint about service and contract

When i moved address within the Netherlands, KPN said I can move and take my contract with me as there is fiber installed at the new location. To my surprise, after organizing the new setup with KPN store, I scanned the new apartment and found no fiber connection whatsoever. I called to ask about this as I had been paying for a service that was “lied” about. I contacted customer service, was a lovely guy who helped me out by organizing am emergency sim card for me with data. He had a technician come out to see if there was a connection. He didn't find anything and then mechanic then came to the house, which said he would have to drill through the roof or wall to get fiber into the apartment. I told him no as the landlord did not approve of this. I spoke to customer service again and explained the situation, they said I should email opzeggen@kpn.nl explaining the forced reason of cancellation and upload several documents. I still went to the store in person to clarify this. I emailed requesting my refund and cancellation as it was out of my control the wifi. I still have not received a reply after nearly three months. I have spoken to several customer service as well as the back office and no one has been able to help. The service has been absolutely terrible besides the first guy I spoke to. I have started to decline the monthly payments as It has been 5 months I have not had wifi nor have they responded. All KPN has sent was a letter that I will be fined 25 euros for not paying the monthly bill. Who can I speak to in order to sort this out. I has been going on for to long and is really exhausting.