False advertising

Iprimis prentended to be Telstra service provider when I signed up I searched the internet for Telstra and phoned the call centre and signed up for adsl only to find out that they are actually Iprimus and they are refusing to cancel the contract I already have a phone line at home with a dialling tone that only needed to be activated , after they sent me a notification that the line is active suddenly the phone line does not work any more , they want to charge me for a call out to come repair it , so I said they should rather cancel the contract they are telling me all kinds of stories why they can't cancel it but I haven't even received a contract or signed anything or provided them with any banking details