Where Is My Free Upgrade?

I bought Minecraft back in 2010 when I was promised every future version for free. I then didn't have a working computer for the longest time. I continued to support Minecraft and play the game by purchasing it again on the Xbox 360 and then again on the PS4 and on iOS. When I finally got a computer again and went to get my free windows 10 upgrade, but it's not available. Please help me with my free upgrade. I am not about to purchase this game for a fifth time. I tried reaching out to another support line and got an auto reply that they were busy and have not heard back.