i94 says 6 months but immigration officer said you can stay only for 1 monh

[ChetanPatil]

Hi my parents arrived in United states on 23rd Jan 2018, they were told by immigration officer at the airport that they can stay only for one month , 
there last visit to USA was on 24 June 2017 and returned back to India on 17th August 2017.they stayed less than two months in USA .They have returned back to USA after 5 months, 
I checked there i94 it says its validity is six months for both, I know its legal document but was not sure why immigration officer said they can only stay for one month, 
he also added that if you stay more than one month you will never be permitted to enter United States again,we had plans to visit many places in 5 months duration and now everything is at 
stake, they cannot cover all the places in one month as they are over 65 years and cannot travel continuously .What should i do now.Should i consider i94 as validity and make them stay for
5 months or should i take i take immigration officer words seroiusly.
Any help would be really helpful.