Bajaj Finserv — illegally taken money from my account

Address:

Karmanghat, Hyderabad, Andhra Pradesh, 500079

I had taken one product on emi from bajaj finance service 5-6 years back and paid all the emi's 5-6 years back. During the emi period i had given authority for them to take the every month instalment from my bank account. After 5 years suddenly took 4999 rs from my account without any notice. When i went to the office they asked me to call customer care... And customer care asked me to email almost one month is done and i sent multiple emails and calls.. There is no proper answer from them.