Link to claim Win10 bedrock edition is not available (Bought minecraft on march 2011)

Hi, 

Referring to mojang website, player who bought minecraft before the 18th October 2018 should be able to claim a bedrock edition version of the game.

I log in Mojang website.
I click on games. Select minecraft. 
I select minecraft bedrock edition, and I click buy. 
(Referring to other users I should be redirected on a page on mojang website, telling me a already bought the game and can redeem a code for Bedrock Edition) 
I get transfered to microsoft website, who then ask me my payment method, in other word mojang website won't recognise the fact that I bought the game a long time ago.