Please clarify about sbi subh nivesh insurance scheme?

a couple of months ago sbi life insurance agent approached me and canvassed about sbi subh nivesh. he said if you invest 3236 quarterly, at the end of ten years you will invest rs129440/- . the company will give equal amount what you invest+ bonus(he said the bonus amount would be more than 50000/-.) he said total amount i will get nearly 300000/- (129440+129440+50000=308880)so i joined in that scheme. but after i paid first installment, i read in a forum that this scheme will give interest only upto 6%. i was shocked by this statement. then i mailed to the concern people to resolve my problem. but i left unanswered. you people please tell me about this scheme. and please tell me is the statement of my agent true?