Ola — Harassment and threatening by Ola

I received a notice from Ola asking me to clear the outstanding dues from Olamoney postpaid which showed 481rs (158rs + 328rs). I immediately emailed them to revise the amount as I paid the 328rs in cash to the driver directly. They responded back asking for proof of payment and I reverted back providing my bank details as well as the ride details. However, they did not respond back. I kept receiving an automated email saying any amount paid to the driver is out of their scope. Since the amount was not adjusted I decided not to pay. But since 2 months I have been harassed and threatened everyday by Ola with 100+ calls, SMS and whatsApp messages threatening me that they will take legal action on me. One executive also verbally abused me over the call. I am so exhausted with this. Whenever I ask them to respond to my email, they say what email.