Poor and Lack of Service from Kia Konfidence

I bought a vehicle at Kia Konfidence and despite having delays to deliver the vehicle which almost resulted in me canceling the deal, I was assured that the 1st installment will be deducted in September and will be on staff rate. I confirmed this in writing and have evidence, however, I was surprised to see a deduction in August and on normal instead of staff rate and sent an enquiry to the Dealership Management, F&i that was doing the deal as well as Salesman. This was about 3 weeks ago and the query has still not been resolved. I have lost confidence in this dealership and its Inability to render after sales service. Now that the deal has been concluded, it seems as if no one cares how the client is feeling and mostly I regret buying a car from them.