My employer charge me 100% medical premium even though I worked 1 week out of that month.

We pay $25 of our health care premium. I left on maternity leave April 8, 2011 was my last day. I returned to work on June 1. During this time they made me pay for April premium. I understand I would pay for May but I work the first week of April to train my replacement.

If I was an employee that quit on April 8, I would not have worked the full month but in Washington State they still they would have to covered me through the end of the month. But because I went out on maternity leave, they made me pay the full month premium. Is this legal?

We also have automatic issued PTO every month. While I was out, they said I did not work fulltime in April or May so would not be issued the PTO. If PTO is issued automatically, wouldn't I still accure it for April since I was actively working until the 8th?