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:
Roblox TOP UP USD $8.47
Roblox TOP UP USD $17.97
Roblox TOP UP USD $46.75
Roblox TOP UP USD $229.91
Roblox TOP UP USD $183.64
Roblox TOP UP USD $53
Roblox TOP UP USD $109
Roblox TOP UP USD $189.37