DATSUN GO Purchase decision- cursing myself

I am terribly disgusted on my decision to purchase the top end GO+ Anniversary model in Apr 2017. My car is giving av mileage of about 10km/lt whereas it claims to give 19.8 /21 Km/lt in city & Highway driving. In Yamuna Expressway it gave 11.3 km/lt. I have visited workshop 12 times in last 5 months to rectify the problem but the incompetent staff are worst to talk about & with no follow ups. The Manager & customer care staffs are least bother to take any suitable action or making any courtesy call, I had to chase them. I curse myself to decide for this model.. avoid it as I have given more than 5000 known contact in my personal & professional circle in FB. Twitter, Linkedin, whatapp, Messanger & social network site about my horrible experience with Datsun Go+ Anniversary model & Service station staff is a nightmare for me. I should have sticked to Maruti model I have been driving over 22 years.
I only suggest that please don't buy this DATSUN GO+ Car as it gulps petrol & you will be in constant trouble unless you have extra stash of money to put through exhaust. My rating for this car is below 1, I wish rating card had negative numbers as well.