Mental harassment and Wrong communication

Dear Sir/Madam I am the RBL bank card customer since from 2years. In the month of Feb 2018 i lost my card and same i blocked from my side. I utilized the amount of Rs 39k and paying 4200 every month upto june but Last month 17th i got a call from RBL collection agent and inform the there is an overdue in my account and asked me to pay 20k and also he told that your amonut not converted for EMI so i paid 20k on 20th dec 2018.After my payment i recieved the statement from RBl bank with no overde and the same i attached for your confirmation. But know one of the collection Agent Mr. Kannana calling to our National Manager and saying that he not paid any amount and he was the defaulter and also saying why you given opportunity for this kind of people in your company bcoz of this i raised 2 times complaint againt him wkth your customer care on 17th and 21st Jan 2019 but still the issue mot resolved. Bcoz of this am loosing my reputation in the company also loosing my job.