Leagues Rewards

Hey i was playing leagues for a long time and i’ve become the rank “professional sports” (10.000/ 10.000)
and i still dont get how the rewards system works.
If i win i get like 50k
and the time i was at (9.000/10.000) and if i ranked up to lets say rank 3/5 ive become as" rank up reward" like 500.000 Credits so my question is
how do i get the 500.000 Credits if im 10.000/10.000 i mean i cant rank up anymore

sorry for my bad english i still hope you understand what i mean lol xd