Internet wasn't cancelled even though KPN said it was

KPN acknowledged my cancellation of my Internet subscription a few weeks ago, but today they have charged me for July. I can't get through to anyone, the chat bot breaks and goes in a loop when I tell it I don't have a Dutch phone number, and I'm abroad this week so I can't call them, even if I could find a number to call. I need to get my subscription cancelled and my money for this month refunded