Concerns but no response and action regarding canc...

Concerns but no response and action regarding cancellation home insurance, 2.5 months now. I sent 3 mails myself and received 2 x promotions from opzeggen.nl with cancellation letter. Weird bad! And the complaint form does not work on the site, how useful is that ?! How can you get this company moving? And then with prompt and correct handling of cases.