1-grid i am owing

i had a web hosting account with them a long time ago, i just got a call saying i am owing them R650, then i asked them how? bcs i should be paying as i go, meaning paying in advance for the service, they are saying my account was setted with an auto renew, i didnt setup any auto renew, that account package is somthing i only use once or twice. Why would a company setup an auto new renew without a confirmation from a client, i have been hosting with a couple of companies, when ever the next payment is due they send email and close down the service, that is what i will expect, why would an auto renew setted as a defualt?