Reliance general insurance gave no claim for my car accident repair

My car has got insured with reliance general insurance. I met with an accident on 19/06/2012 and my car back side and side door got damaged. I have given the car for repair in toyota service center trivandrum. They have contacted the reliance general insurance branch in trivandrum and they approved their estimate of repair the vehicle. After the repair the toyota service persona called me and said the insurance people not been accepting the claim since the policy has issue with ncb of 20%. Until then I was not knowing that they have given me the discount.( Since the business is very competitive these people are giving us low coat to get the business and later on cheating us). Then called reliance general insurance several times and each time they said they were e verifying the records and may have issue the amount soon.. finally I called today(10/07/2012 12:13 pm I called reliance general insurance co ltd 3 rd floor ( level 5 ) trans towers vazhuthacaud trivandrum 695 014 to the phone number 8232 and talked to mr. Sreejith who has th done the survey of my vehicle. He said ,since I have a claim with the prior insurance company (chozhamandalam general insurance ) and have enjoyed the ncb this policy is no longer valid.. but the policy has been issued before 24/06/2011 and why they didn’t check I’M I eligible for ncb? be truth I was not knowing that I have got the ncb amount in this policy. More I have done one claim before with the same policy before 2 months back and that time they paid the amount as chq. So my question is why they didn’t check this condition on that time. Unfortunately my policy has got expired on 23/06/2012 and I have gone for bahrathi axa insurance hope because of this these people may crazy on claiming my amount. Plz advice.