Kia Diep River bad service

My issue with KIA Diep River has been unresolved since November 2023. 20 November 2023 my vehicle was supposed to go for a service. I booked the service and took my vehicle in on the day however due to an employee of KIA (not sure which branch) who in error put details of another KIA owner (Vin number) on my profile Liquid Capital would not allow the service to be done. KIA Diep River eventually got Liquid Capital to fix the vin number mix-up by 8 December when I received an email from Mahendran Reddy (Service advisor) at KIA Diep River. In this email he also stated that they now are waiting for service authorisation from Liquid Capital. I have been told that he no longer works in that department. I have sent him 2 emails as well asking for an update and those remained unanswered as well. Ever since then I have been phoning them on a regular basis to get an answer. I just get told that the person who can assist in unavailable. I need my vehicle serviced and I told them that I better not lose my maintenance plan.