IIFL — Harassing with calls

I have purchased a product from byjus and for that am paying EMI's PER MONTH..my payment got delayed this month due to some personal reasons and they are harrassing me n my husband with their calls ...i mean they calls 8-10 even n that is too within an hour ...i do reply some of them n tell them the time when i will pay their EMI but continue to call n everytime a different representative is calling n telling the same thing to everyone ...now am fully mentally harrassed by them that i want to discontinue with the course also n want to file a complaint against harrassment n simply don't want to communicate with with them at all.