Except they return it as account credit not as actual money because Linode doesn't want to fall into the high risk category of payment processing because they refund a lot. If they just did hourly, or even daily, billing I would use them. But I don't want to spent $20 for what ends up being ยข75 of usage and then being forced to either use or lose the other $19.25
In the past I've done what you've described and then asked for a refund to my credit card. Within minutes they processed the refund. Can't fault them for that.