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 $6.1
Fortnite ACCOUNTS USD $8.99
Fortnite ACCOUNTS USD $9.3
Fortnite ACCOUNTS USD $16.07
Fortnite ACCOUNTS USD $26.78
Fortnite ACCOUNTS USD $1.93
Fortnite ACCOUNTS USD $5.57
Fortnite ACCOUNTS USD $19.28