Thanks for the query.
Dandruff is the result of excessive oil application compounded by a fungal overgrowth. So consider discontinuation of oils and start using an antifungal shampoo everyday for first week and then reduce the application to twice a week for maintenance. You should keep the shampoo atleast for 5 minutes on the scalp for it to act. This should solve your problem. However if problem persists, consult a Dermatologist for proper diagnosis and treatment plans.
Hope it helps you.