unable to fix my car

during the month of june i booked my car in at aden motors with the manager known as Baadier . reason for repairs was to fit cambelt and a price of R1.300 was given.days later i was asked by the owner known as Makkie to take my cylinder head to the enginneers wich i did ,the head was dropped at the garage in less than a week .i went back to the garage to see if my car was ready to use ,and i was told that something is wrong but the owner assured me it will be ready in a weeks time. i went there then he told me theres something wrong with the headcylinder so i callled the engineers they daid i must return the head to see what was wrong .the owner told me to get a mechanic to take it of wich i did so he told me the mechanic cant work on his premises .today iwent there he told me he,s gonna bill me for my car that is not fixed by him a blue volvo v40 non turbo .i need advice please