Car issues nissan

Good good people, sometimes we got ****** without gun point and lot of money,by the so called motor cars dealers or mechanic work shops in south africa, last year 2024 September, I got stucked driving towards pretoria N1,due to diesel tank contamination by 95 petrol,towed my car back,to engen garage Tembisa convenient center, same night due the managers collaboration ,petrol was drained out,the problem remained was hardstart on my car,mechanic advised to give it a week and if no changes notify the garage,I did all that due to that the other day car couldn't start at all,they have escalated the matter,gave me go ahead to Nissan workshop were I service it all the time,my car is Nissan Xtrail 2.0 dci,during the arrival in Nissan premises with tow truck,lady asked what's wrong I explained from were it began till that day I brought to them,she said we will diagnose it,and let you know,later she called and saying they will drain petrol and change fuel filter,I said if you believe is that it's ohk,then they quoted me,following R7300,after a week she called and say ready for collection, in my arrival my car still have hard start,I asked her why?she said give it a week it will fade away,if not, bring the car,I drove the for a week matter still remained, I called her indeed she said bring it,then what shocked me she demanded diagnostic fee again,I said no ways,I paid you for this problem already, I asked her manager Sanele Chm Nissan midrand, he said they will diagnose it and they will let me know,I left to work indeed he called later claiming that is glow plug relay need replacement, I can come to fetch it,then I said quote me if you believe is that sir,since he never quoted till today,I am getting starked every road I take driving this car,I sent email,yo him no respond,I sent emails to nissan south africa,no respond comes out ,called them multiple times,keep on saying they will get to me no one does ,still in the dark even today.i am appealing to any help my money is gone remained with no job done.helped by Vanencia Ndlovana