OnePlus India — Cheated by Oneplus service team on extended warranty

Hi,
I have purchased Oneplus extended warranty plan for Oneplus 9 phone from their website.
After that i have placed a request with Case ID:[protected] to attach the warranty to my phone IMEI no. This request i have created on 7th June 2022. Still now the issue they have not resolved. I have mailed them more than 10 emails and hardly they are reply to them. I spoke with the customer care team but unfortunately only giving false assurance but no resolution .
I am not in a situation which cant be handled by me. Please help me in this regards.