ISP Troubles

[T180985]

I used to get my broadband through a company i worked for who resold it from Telstra basically they told me i needed to move away or they would cut off my line, i was given a mac code which i gave to my new ISP but when they tried to use it, it turned out the tw@ excuse my french were i used to work decided to cancel the line before i could migrate it away so i decided to call telstra directly and they were going to give me a mac code but again this tw@ jumped in and told them not to talk to me so im now in the position where i have dsl on my line but cannot log in. what can i do to force them to just cancel the line asap so i can just sign up else where? its been over a week now and the tw@ is just messing about as per normal