Mutual Fund Account Given To Someone Else by Aditya Birla Mutual Fund

I have a mutual fund account in Aditya Birla Mutual Fund. It has about Rs 3 lacs worth of stocks in it. History of transactions for this fund shows that Rs 5000 was once deposited in 1995 and no purchase and redemptions have happened in it since. I always thought that my father must have deposited this money for me (I was 14 yrs old in 1995). I have shared this with my father and he always maintained that it is quite possible, since he was very active stocks during that time. But being such a longtime ago he has no paper records from 1995. This last few years I was able to see this fund associated with my PAN number - all contact details (email, address, PAN number, mobile number etc) in the fund belonged to me. Account statement by Aditya Birla even till Feb 2021 show my contact details in it. However I am not aware about the bank account associated with this fund because I never planned to redeem the money. On 10 Feb 2021 I received a SMS stating that someone has changed the bank associated with the fund. I reached out to customer care, and asked them how that has happened - but they didn't give any satisfactory reply. I tried to change the bank account but couldn't because I needed to provide a cancelled cheque of the now associated bank account. After this I got busy in my personal life because my father-in-law expired on 17 Feb 2021, and I considered change of bank account as a pending task at my end. I received no SMS or emails related to this fund after that. On 10 Mar 2021 I received a SMS that someone has changed the bank mandate associated with the fund. Alarmed I reached out to Aditya Birla Customer Care. They told me that on 16 Feb 2021 they have changed the PAN number associated with the fund. I asked them how it is possible because as per SEBI regulations - the PAN number can't be changed unless there is no PAN associated with the fund or not a valid PAN associated with it. They have no answer for it. On my request they blocked the fund so that no redemption can happen in it. And they started an investigation into it. After few days they informed me that there was no PAN number associated with the fund till March 2016 and in March 2016 - my PAN number got associated with the fund due to mistake by their software. And that is why since Mar 2016 - all account statements are reflecting my PAN. I asked them that how did contact details got associated with the fund. They replied stating that my details were picked up from SEBI maintained KYC database. I replied saying that in 2016 - as per KYC data my email id was a different one. Not the one associated with this account. They don't have a reply for that as well. Instead they are saying that the other person is able to provide a deposit slip from 1995 which I am not able to. Therefore they want to give the fund to that person. Can I file a civil case against Aditya Birla Mutual Fund to recover my money? Or can I go to consumer court?