Hyundai Motor India — Service providers using counterfeit engine oil

Address:

Porvorim Bardez Goa

I own Hyundai Creta sx 2017 model my name is Ravishekhar Nipanikar resident of merces Goa and I service my vehicle at M/s Alcon Hyundai porvorim Goa. My service provider is using duplicate engine oil at time of service and charging exorbitant amount of Rs 350 per liter for duplicate engine oil
I requested him not to use counterfeit engine oil and purchased 5 liter engine oil of reputed company with specification provided on service manual of Hyundai company
The service provider agreed to use engine oil provided by me but mentioned on my bill that I m using counterfeit engine oil
I lodged complaint to him on first instance but there is no response and on top of it his maintenance manager and maintenance team is threatening me that they will cancel my extended warranty
The service provider is using counterfeit engine oil and charging exorbitantly to all the customers and making mockery of entire servicing processes only to earn extra money in servicing and also his maintenance team is threatening customers
Please resolve the issue with service providers M/S Alcon Hyundai at Goa