Rules not explained

I got a car rental yesterday from Bidvest car rental in Kruger Mpumalanga Airport.i was never told that should i have an accident ill be reliable for the payment of the access fee.Hardly 5 minutes after taking the car a huge bukkie bump us at the back was with my 2 year old.then i phoned them to inform they then started telling me that im relying for all the payments..i felt that was so unfair of them...at least they should've explained to me and if im ready to take the risk or not ...Not after ive already had an accident. Im left with this huge debt that i don't even know how im going to pay them.its even worst i was not the one at fault this guy bump me at the back.