Tata Consultancy Services — Facing issue in tcs alumni portal

Hi, I am facing issue in tcs alumin portal registration. I have resigned from tcs on sep 2nd 2022. After resignation when i tried to login to tcs alumin portal it's showing invalid user name and password. I tried to reset the password but it is showing invalid username. I have tried registering again but i could not it is showing that the details is not matching with the databse. It's been 4 months i have raised multilple tickets in tcs alumin portal contact us but i didn't got any response. Latest ticket numner: 1009439. Please help me on this issue.