There seems to be a difference between the available Store Credit of yours with the site currency you had picked previously. Would you like to:
Fortnite ACCOUNTS USD $21.77
Fortnite ACCOUNTS USD $3.27
Fortnite ACCOUNTS USD $97.94
Fortnite ACCOUNTS USD $97.95
Fortnite ACCOUNTS USD $27.21
Fortnite ACCOUNTS USD $18.99
Fortnite ACCOUNTS USD $28.99
Fortnite ACCOUNTS USD $35.99