DEBIT ORDER WITHOUT PROVIDING SERVICE

I got a debit order without them installing a new system yet. i was still waiting to call them when i have money for the installation. then boom i see a debit order. i called to ask why i am charged when i dont even have the alarm yet . i am told because i signed. Cant they see that there is no alarm at all in the house they are billing, that makes me question if at all they can see should i need emergency assistance