Bajaj Finserv — no dues but still all my contacts on phone are receiving calls from bajaj finserv - they take all contacts through application and harass peopl

One of my friend took a loan from Bajaj Finserv RBL Card and paid all her dues and closed that credit card last year and now all her contact details are getting a call from Bajaj to pay more 15000 to close, she went to bank and bajaj finance and they told everything is clear but then why Bajaj people are harassing and who has given them authority to call everyone on the contact details of the customers.