State Bank Of India [SBI] — Unauthorized and unknown banking online transaction

Address:

Patna, Bihar

I am a salary account holder in State Bank Of India and my account is 30+ years old. I have not taken any net banking facility or done any online transactions till now.
Also, I don't know how to use it online, but from few months from SBI account many online transactions have been done without my knowledge. From 17th June 2023 till 12th Oct 2023 many transactions have been done which says "OTHPG paytm services noida". For other transactions I was getting messages but for these transactions I didn't received any message or call. The deductions were done in small amount and on regular basis and I lost total amount 2, 53, 284.59 which is a huge amount for me.
I have never shared my card details to anybody and when I contacted my branch, they don't have any answer. I don't how is it possible that bank have no information.
I am in huge loss, I need refund of the amount I lost. I have all the details with me.