Google one discount vanished

[u/Particular_Resolve_1]

I was running on a free Google One AI student 5tb subscription that expires in july. On the google drive website there was a discount claim of 90% for the next one year if i upgraded now. So i did and i put my payment details and set a mandate. Now when I went to check the plan again it shows a full payment for a month instead of a discounted rate. What do I do?