[2023] everything is gone

I put in a case for helping me link a different Xbox account since for some reason I had a Xbox account linked to my pc account. After a month I finally got an answers and I was able to get the Xbox account linked to my Ubisoft account. Now when i log on to my pc or my Xbox account all my old 7+ year Xbox progress is gone, I owned almost all elites and spent over 400 dollars on this Xbox account and its gone. I log into my Xbox and went on R6 and its the same as my pc. I need help. I want all my Xbox progress back, please someone help.