Paytm Mobile Solutions — Fraud and harassment(paytm postpaid)

While signing up for paytm postpaid it was shown that bill can be repaid as an emi. I had availed 6733 rupees from paytm postpaid. But when I tried to pay no emi option was shown for bill repayment.they shared my number with random people/third parties. I have been getting 10-15 calls evryday from third parties and messages as well.
They are asking me to pay almost 50% of the availed amount as late fee charge. My total amount to repay is over 12000 rupees. No customer service from paytm is contacting me only third party people are. I have tried to reach paytm customer care but haven’t gotten any response.