My colleague received the option to cease contributing at age 60, but I did not, why would that be?

The option to cease contributing to the Fund at age 60 is only open to Existing members, that is those who were members of the Fund on 1 April 1989. If you joined the Fund after 1 April 1989 you do not have the option to cease contributing at age 60, however this option is available at age 65.