How long do I have to get my trade-in vehicle back from the dealership?

I made a poor decision and traded in my neon for a Jeep Cherokee which is what I wanted to begin with. I love it but Ive had nothing but problems with it in the whole week Ive had it. I bought it as-is on July 4th and called them the same day and told them it needed some things they fixed them except the gas guage and now Im driving around with a baby and a gas jug. I asked them several times for my vehicle back and I keep getttin a run around. Please help