Shattered and saddened by service at Mcduling vw

Im so disappointed by vw diddnt expect this from them as i trusted them with repairing my car as i saw them as better than backyard mechanics .I took my car to McDuling vw booysens because it had problem of driving for 20ks nd show EPC caution light then loose power i took it there on 30th of april 2018,they called me after few days and said it was cam shaft holder and the repairs will cost me 7000 gave them go ahead next few days they called and said they test drove it still had EPC so they did another full diagonistic the prob is now throttle body and wiring the total cost 17000 i gave them go ahead they gave me the car after a day it still had EPC took it back they said its injectors itll cost me 6000 or i can go fetch them and get it fixed myself so i opt for fixing myself now they are saying theres carbon buildup.theyve stripped car the mechanic said im still going to loose money should rather tow it and fix it privately.they gave me a courtesy car for 3 days and came to fetch it while i was at work and they said ill see how i get home.