contribution based esa and ni credits,

hi, i have been on first incapcity benefit whichj changed to esa, whenever, 2016 i think, i phoned up future pension forecast as i don.t have the id to do it online, she said i had 41 years and would get full state pension, she did mention i was paying class 3 ni, which i thought was for the self emploed, this was a couple of years ago, so i don,t know what to do, phone esa and ask when it changed to class 3 or phone future state pension, and ask them, nobody wants to make the dreaded phone call, i am still on legacy esa in support group, no income related payments and not means tested, i also recieve pip enhanced on both daily living and mobility which runs to 2032, my retirement age, i know i will be reassed the year before, i know a lot can change between now and then, but if someone could give some advice i would be gratefulm, i am still on legacy esa and still recieve my payments no problem, never been self employed
thanks

my lat two uprighting letters say i am in contribution based esa?

i must be paying class 1 contributions, it was only an off the cuff comment from woman at future pensions, i was awarded contributed contribtion esa in 2011 and every uprating letter since has said i am in contributions based esa support group, i have about a tenner a week for work pension i recieved in 2014, and i inform them each year when it rises, if i was paying class 3 surely they would have noticed in the last 22 years, how did i build my state pension up to full amount if i didn.t, think i will phone future pensions again to get new statement and take it from there