Cant download Minecraft

Hello! so i bought minecraft back in 2012 or something and have played it on all my computers ever since. i recently wanted to start playing it again and headed over to mojang to download it. there i saw the new minecraft windows 10 version, so i thought id download that, since u can do that if u purchased the original minecraft before. so the problem is i couldnt download either the windows 10 version, and not even the basic version. i have had this game for so many years, and now i cant download it again without having to pay for it. and yes i bought it on this account, because this is my only account. if u could fix this i would appreciate it. 

best regards!