Health Insurance back-dated to date of qualifying event without permission or request.

My girlfriend recently moved to California on September 12th. She signed up for health insurance through blue cross blue shield using her employer provided online forms on October 4th. It required her to put in the date of the life changing event, and she entered September 12th. Her assumption was that her insurance would begin at the time of the first premium. There was no other information provided to suggest otherwise. October 16th she received her benefit information which states that her insurance was effective September 12th, and today (October 18th) she received her paystub and found out that $100 had been withheld to cover arrears.

At no point did she request that the health insurance be back dated, nor was she notified at any point during the signup process that it would be back dated. She has no use for insurance that she did not know existed and had no way of utilizing because it was in the past.

Everything we are reading online is saying that for special election periods health insurance goes into effect on the 1st of the month following the election. So we feel it is reasonable to have been notified if anything was going to be different.

Does she have any recourse for recovering the withheld amount and getting things fixed so that the insurance went into effect either when she signed up for it on the 4th, or when she paid for it on the 18th?

Thank you