Altech is harrasing me!

I have been battling to cancel my supscription with Altech. They stopped debiting my account, and I was not aware, I only became aware when they debited 3x the normal premium, when I called to enquire, I was informed, it's because of the previous months that was not paid. I was never informed, and now I am told to pay up. They cannot answer when I ask, why did they not debit? My account always caters for my debit orders. They stuffed up, now I have to pay for their incompetence. I have since sent numerous emails to cancel- but they just ignore> they send me from one debt collector to the other> I am tired of Altech, and I need a full investigation on what happened. I cannot be penalised for their error. ALTECH PLEASE STOP HARRASING ME> I DEMAND A FULL INVESTIGATION