Cancellation

My partner won a scratchy and was convinced to come in their office in Parramatta to collect his price!! I didn't wanna signin but my partner was convinced even with his English not 100%...,I'm responsible for our financial and bills so I get the last say anyways but at the time I was 7 months pregnant and after sitting there for over 2 hrs trying to read and finding out exactly what they do I was getting too tired and lost concentration to what paperwork I was rush to sign in the end but we both agreed that the new guy who signed us up failed to mentioned the cooling off period and the manager walking around went through our paperwork and I saw him add 0's to our income so that our paperwork pass the bar to join!!!
Now my partner is out of work due to injury and I'm due to give birth any day and can't afford the $370 a month payment (which went up from $188 after 3 months)
Added to that was the fact I tried to book my mum to come see me for the birth and found they quoted me flight prices more than what I can find myself online!
No one seems to answer or help with my questions to find a way to cancel!!! Plssss someone help!!! There is absolutely no way for us to afford this :-(