Very poor and frustrating customer contact

I am trying to call Altech Netstar from yesterday to arrange cancellation of my tracking device for next week. Their phones line do not go through at all and keep dropping calls. I have been trying from my cellphone and landline with no luck for 2 days. The calls drop as soon as I select an option. I have even sent a twitter request yesterday morning, which they only responded to last night, requesting my phone number. So far nobody has called me. I sent a cancellation request via email yesterday at 12h01 as well, to which I have had no response so far.

Have they simply not picked up that there is an issue with their phone lines? There is no alternative number, only an emergency number. What does it take to get through to this company? It feels like I am dealing with a government department.

My account number is: ********** 4.