Bajaj Finserv — Untimely deductions

I had bought a phone on EMI card provide by Bajaj finserv
on 28 /12/2019
However Since I was unemployed from feb Last two payments were made late Cause even if I had money in my account these people even after telling them to deduct they wont. its their own fault cause I told them to deduct payment, Last bpayment was in december 30th of 5788, and the agaent told me that the fine was waived off, and he closed the payment. but even after that Bajaj guys kept calling me sayig I did not pay the emi and I thought this might be scam I kept ignoring untill yesterday when they deducted a charge of 970 from account . Please look into it, the customer service wont return my calls. it was a no interest emi, ut I ended up paying 36288 when bill was only for 34999, they have my bankdetails and they are deducting money anytime they want