fastmail 降级不退款吗？

[adeweb]

一月份试用了几天fastmail，然后买了Lite Plan，又试着升级Full，感觉Full和Lite差别不大，降级后没有任何退款。
有个支出显示Adjustment to balance $-9.98
（Current account pool balance: USD $0.00）
后来在帮助文档里找到这么一段：
Credit for unused subscription
When you upgrade or downgrade your account, we will take the amount you paid for your previous plan and credit the unused percentage of that towards your new subscription. Please note, if this credit is more than your new subscription, the remaining credit is lost. It is not put towards any future renewals.

我就这么损失了9.98刀么？头一次遇到这种降级或取消不退款的情况。