try and cancel contact

I need to cancel contract. I phoned 20+ times. Every time they ask me for defferent things on contract. I cant figure out exactly what they need. So I try and ask what they want from me to cancel this contract-she just tell me- phone back when you got all the right info-and put phone down in my ear!!!! How do I cancel this contract- after I have phoned so many times. And every time they have another story? How on earth must I know what they want if the person just put phone down on my ear? And I dont have her name!!! Because she said it very unclear while laughing in my face??? Where else can I go to cancel this stupid contract??? Because phoning doesnt help!! I phone and phone. And just get either cut off the whole time. Or bad ****py attitude with No help... please help or give advice to where I can go? I need to cancel ***- its my contract-my mom used to use it, but passed away on 22 feb this year. I want to cancel and put it over to plain prepaid. Please