Ola Cabs / Ani Technologies — payment issue and disturbing mental peace of a person

I have taken a ride on 01.4.18 and paid the driver in cash of Rs.531 but for the past 1 year daily am getting around 4-5 calls from ola asking me to make the payment by credit card and getting messages like they will raise a legal complaint against me.. and torturing like hell with their frequent voice recorded calls and messages and taking away my mental peace..When I paid my due cash why the hell Ola is torturing me like anything.. They are not having a proper system in place instead torturing the genuine customers like anything