Bad service

I bought a second hand car with them...BMW 323i I drove it a week...it was giving me problems.then I had to send it back...they said they will fix it now it's a week....they don't update me..only when I am calling them..they then telling me that some parts that don't have...I have to wait that don't know for how long ....no pull car now i am paying insurances for the car i don't even have....