National Security - No answer to phone calls or emails for 2 months - YOU'RE FIRED

My alarm triggered in December, and I received no communication from National. The next day I phoned them (it was luckily a false alarm) only to discover that they do not answer any phone calls to their customer service line. After a few days of trying to contact them, I decided that an emergency service that does not answer phone calls or emails is not a useful thing to pay for. I emailed them in December to cancel my service - and have received no reply. I emailed them again in mid-January to tell them that I am putting a stop-order at the bank to prevent any further payments to them. Still no reply. Perhaps HelloPeter will alert them to the fact that they shold come and collect their radio equipment and that they are fired - no communication channel I have tried thus far can contact this 'emergency service' company.