Angry Client of Car Repairs to her car

I am a single lady of 57 years old who works very hard to make a honest living. I rent a room in someone else's home and I drive a very old car that costs a arm and a leg to maintain on the road. I recently had a very bad experience by a mechanic in Brackenfell, his name is Albert. He came recommended by a friend, and with good trustworthy mechanics being scarce decided to send my car to him. I explicitly told him not to do anything on my car without my knowledge and not to proceed with anything until he consulted with me first. The next day he messaged me late in the day to say my car was ready for me to collect. I rep**** by asking what the problem was and how much did it cost. He did not reply to me at all. I then messaged my friend to go to him to find out what was going on. My friend then messaged me to say that the amount owing was R2130 and that my engine needed a engine flush and new oil filter and oil change.. I could not make out the mechanics hand writing only that the oil cost R400 for a 4.5L (which you do not get in 4.5L) and engine flush for R158 and the balance of the R1572 was for the labour. This was the most expensive oil change in history that I know of. I repeatedly asked him for the invoices of the new oil filter which he claimed was from the agents in black and white and the so called 4.5L oil that he had bought for my car. He did not reply to any of my messages and then still proceeded to block me. I then phoned the agents of my car and they told me that the oil filter for my model car was no longer being manufactured and it was impossible that the mechanic had bought a new agent filter for my car. This mechanic really has under estimated my intelligence by telling me it was a 4.5L oil he purchased and a new agent filter. And then to charge me R1572 for a oil change is a total rip of. I am extremely angry and in good faith paid him the full amount on the invoice only to be caught like this. He goes under the name of Albert's Hobby Shop in Brackenfell Cape Town. Please people be careful and be very aware of being caught by so called mechanics like this. Money is tight for all of us in this day and age.