State Bank Of India [SBI] — updating mobile number in core banking

Address:

New Delhi, Delhi, 110042

I opened my account through the YONO app and the number I used then is not with me right now. So, I needed to change the mobile number and I was suggested to do that through the internet banking option. But now I get all my bank SMS alerts on the new number but the OTPs for the transactions done through the debit card is still being sent to the previous number. I contacted the customer center and they said that I need to update the number in core banking but I have been unable to do that since then. I also contacted the home branch but that has not worked either. So, what should I do to update the number in core banking? It has been months and no resolution has been provided from the bank.