Incapacity benefit query

I claimed IB in August 2007 and got a letter saying I was not entitled to any payments because I hadn't paid enough National Insurance contributions. I had worked from 1 April 2005 until being signed off on 24 July 2007,therefore paid 28 contributions.I was sent for a medical and deemed unfit to work and then got a letter saying that I didn't have to attend any other medicals until 2012,and that they had contacted my doctor saying that I did not need to submit further medical certificates until I was recalled.

I rang them to ask if I could claim the new ESA but was told that I was not eligible because I am receiving Incapacity benefit.But I don't get any money,apparently they only pay my National Insurance stamp.

I have since learned that the requirement for actually getting the weekly benefit was to have paid at least 25 contributions in the 3 years prior to claiming benefit. SO I rang them again and was told it had changed to 36 contributions in 3 years,so I didn't qualify.can anyone tell me if this is correct? I get no other benefit and only my stamp paid at the moment.