回複：回複：This is strange.

You are welcome. As you told them about the mistake already, no need to follow up -- till they send you another bill. Remember the time you called and people you talked to. Very likely, they will correct it themselves. (There were cases I had bills overdue for 90 days. No big deal. ;-))

Congratulations on your pregnancy! Don't worry about this kind of small things too much. Be happy is very important for having a healthy child ;-))