How long have you owned the computer & system in question?
Are you within reasonable distance to access a retail Apple Store
or authorized reseller with service department, or a Genius bar?
That'd be worth a call to ask about setting up an appointment to
talk to a Genius or product specialist who could help resolve this
issue. Or learn how to turn off the problematic parts of keychain.
Did you purchase the 'extended AppleCare Plan' to add 2 yrs
additional coverage plus full support past first 90 days grace?
This essentially provides a three year coverage if althogether.
http://www.apple.com/support/contact/
There is this page ^ at Apple Support online to ask about
options. However after 90 days, there would be a fee to get
any headway in phone support; and the cost of an extended
AppleCare plan is one way to avoid a fee for each issue, after
the complementary 90 day support expires; leaving only the
rest of the first year of Service, without Support.
It could be easy to miss something, in all this mess.
Sorry to not be of much help... 😟