JOICO is a pro line and I haven't seen it at drug stores or Sally's. I just buy mine at various salons and beauty supply shops around me.
Here's an older link from this site where ppl talk about where to buy it. Maybe it's still sold in one of those places (like certain Rite Aid stores)?
If nothing in that link checks out, I'd call a couple local beauty supply shops or local salons and inquire (someone should have it). ... Or maybe just order from Amazon or ebay, etc.