Cannot Cancel Subscription

When signing up they seem to be on par. When having to move, they quote very quickly before even knowing the details. That got me worried, but not too serious. Trying to cancel the service is impossible! 7 calls, whatsapps and email later, still no response. Everytime someone will call back, but nobody does. I am having to cancel the debit order from my side and would then expect a non-payment charge from them... Absolutely pathetic service.