Bajaj allianz motor vehicle insurance no benefit

Dear sir / Madam... in nov 11 I have insured my car wagon r from bajaj and in mar 12 I got the letter from them mentioning that you will not get the benefit of ncb so pay rs.1300/- Aprx, after that I spoken to there customer care dept they said to ignore it as it is a systm generated letter and there is nothing to do, aftr that in nxt mnth I again rec a letter with amt of rs. 00/- Aprx and now after 8-9 mnth they are saying I have to pay rs.1800/- + Rs.1600/- For adding cng which they have not done earliest after commitment. Now I told them to cancl my policy and I have renewed it from oic. I have to bear ncb loss for 2 years due to bajaj I.E. For last year and for this year too as I have cancelled my policy and all the formalities are done from the beginning so ncb benefit is not applicable... my last policy is from iffco tokio policy no- 2105 which was valid till oct 11. Please help me out... for any other details or related mails/Documents please let me know.