need help

i bought a vehicle on the 12 july 2019 nissan qashqai was told by the sale person there is a 30 day garantee and he advised me to take the warranty which i did. on the 29 july 2019 lights came on my dash and vibration on brakes called them up they said call warranty called warranty they said the plan kicks in after 30 days. called mc carty sales person again he says will speak to his boss. she says they will send it to nissan and i must pay for diagnostic. so contacted the dp and had a meeting to which he pulled out paper work that stated once vehicle leaves dealership they are not held responsible for any repairs which was not told to me upon signing. sitting with a vehicle that has a problem with no help from them what so ever.