L & T Finance - Company asking to pay interest for their technical problems

I am a middle-class salaried individual who has availed a * wheeler loan for **,***/- and has regularly paid all my monthly E.M.I's. But the company authorities want me to pay ****/- rupees now for getting my NOC for the vehicle and they claim that I did not pay my E.M.I on time for about * or * months last year. Reality is that the manual agents who collect the E.M.I did not come and receive the E.M.I amount on time for those respective months. The same was escalated to the L&T Authorities when they called me in the same month and I was clearly informed via recorded phone call that I need not pay any interest as it was a technical problem from their side and they also intimated me that manual agent will no longer be present and asked me to pay EMI money in their office at Kukatpally. I had to lose my petrol, time & money in travelling there every month to pay for the rest of the EMI's. Now, the company again asks me to pay that wiped off interest amount after the entire loan amount has been cleared because of their technical issue and they also threatened me via phone calls that NOC will not be issued and they will take away my vehicle if I do not pay that money.