Can my work charge me an insurance premium for this?

My work's health insurance cancelled our whole company (we probably didn't pay the bill.) We went 15 days without coverage and didn't have to pay a premium during that time. However, I picked up some meds and payed for them out-of-pocket. My office said that they would reimburse me for those, but now they're saying they're going to deduct a copay and a pseudo-premium (by reimbursing me, they're sort of providing insurance coverage, which has to be paid for). I paid $70 for my meds. I would like to be reimbursed at least $50 (that's $70 less 2 $10 copays.) Human Resources doesn't have the actual numbers yet but they say it will be closer to $10 or $20 after they take the "premium". I can understand deducting the copay because that's what I would have paid anyway if we would have had insurance, but it seems wrong that my office is trying to charge me a premium for doing this. I live in CA if it makes a difference. Can you help, or at least point me towards someone that can?