HIS query

Hello everyone, can anyone explain me about HIS and it's duration and amount it cuts from salary..

(I joined on Nov and on jan ..before completing my 90days of service I had enrolled me and my family(2 members ) in HIS but from from 7500 is cutting from my salary monthly m, but as per my knowledge it's 1 yr scheme so can anyone provide me where im doing wrong . As mentioned in offer letter it should be on yearly basis)

Already paid 14k in HIS including fab and March....

Please provide me some suggestions ....and can we cancel it ??