repair not done

Good Day,a few months back my dad bought me a Navara from an auction,i decided to take it to Nissan Silverton to be checked,i was told that it had a few faults of which i need to replace,i gave them a go ahead and i went back and paid it,a few days later i took it back for service as it didn't have any service history, i paid the amount and when i collected the car i was never given a service book,i asked and they said i need to buy it. I was then advised to replace my clutch kid,when i asked for a quote i was told an amount and i went elsewhere, it was done and it was fine,recently i have been having the very smell that i got before, i went back and they told me it was the silicon from an exhaust of which i have to wait until it burns and it will go,the next thing i hear a funny sound from the engene and i immediately went back to the garage,when i got there they said it was nothing it was just a seat belt,i left,but i still have the smell and the noise,and my clutch was adjusted again,spoke to Lavonne this morning and she says i must pay for them to strip the car again,what do i do in this case?i cant be treated like this after i paid so much.