Consumer Redressal

I have purchased a laptop from croma by using Tata Captial FInancial services finace option. Every month the EMI is to be deducted on the 3rd but till 8th or 10th there is no EMI deducted from the ECS and after 10th of every month, their collection agent calls up to pick up a cheque. Since the date of this cheque is post 10th they charge me a penalty for late payment of EMI for no fault of mine. I have sent 2 emails to the Tata Captial customer care and I have not received any reply. They have not even started my ECS!. After the 5th of every month I get calls from their team for payement like as if i have delayed the payment process. I need help to resolve this as they are harassing me and no one answering my calls.