Poor customer service

I took my car for diagnostic ,because engine had a knocking sound and my car was checked and I went back home to wait for quotation . After 3 days I got quotation and l decided to take my car on Thursday for them to start working on it. They promised me that they will take a day to fix my car, but they took more than 2 weeks .The reason I was given was that we are still waiting for car parts .after 7 days I decided to go and take my car because they said it was finished only to find out that my car is not starting and when my car went to their workshop it was driven there.i had to wait another 7 days .They told me a electrician was called to look for electrical problems that were hindering the car to start.Next thing mechanic called me for workshop asking for permission to open the top cylinder head cover and I gave permission because it was about 10 days without my car.Then later I was told the car is starting but I had to wait 2 days because they were testing it .Almost after 2 weeks my car was collected,I wasn't there I had to wait for a week to see my car. First problem was the start problem, I had to pump accelerator or step on it before starting, the second problem was oil leak from the oil plug which was not tighten and I had to buy another oil. The third problem one reverse light and one number plate light was not working and head lights were not illuminate bright at night but they made me install new light stark for head lights to bright.they also changed my timing kit but the car was making loud pop sound and losing power when u shift from 1st gear to second gear. When I complained about the problem they asked me to take the car back ,the car was taken back and nothing was done to the car ,I was given another list of things needed to fix the car .and one of the things was camshaft but last time when they opened my head cylinder to remove lifter ,they didn't say anything about camshaft being a problem.