Retroactive back pay not being paid out possibly.

I started at my job in June of 2015, fast forward to the June 2016. I started pestering my manager about my yearly review, says he has to wait for HR to give him the paperwork to fill it out.(Note: we didn't have an official HR since the one we had left, so our business manager was running HR.) Continue a couple months my manager starts having a mental breakdown about his divorce goes into a rehab December of 2016 and gets back January 2017. Now it is June of 2017 he finally gets around to completing my evaluation. I confirm with our HR that he submitted it and ask about timelines, when I should see the raise and when the retroactive pay will be paid out. She tells me that company policy is the retroactive can only be paid out to January 1st of 2017, so i will be missing out on the pay from June to December. Can they do that? Trying to figure out what options I have that I can follow up with.