I accidentally overpaid my phone bill last month, so this month...

I accidentally overpaid my phone bill last month, so this month I get this line in the bill. If I could offer some editing advice: why not say "The total balance this month is nothing, and you've got $47.08 credit on your account"? How would that not be way more clear than using the same line you'd give me if I did owe you money, just with a little tiny minus sign next to the amount? Also, why do I need to "please pay by" if there's nothing owed? Why doesn't that say "Take it easy until…" and then give the date my balance runs down to zero and I need to pay up again, which is in two months?

It would cost them two seconds and a line of HTML (like a "if, then" kind of thing), but it would make thousands of customers happy if they put in that kind of effort.