Can they? As you have established, they did - so "can" isn't really the issue.
Your hope appears to be that you can sue them over the mistake. At times people bring lawsuits even though they have no damage (assuming that it's not a necessary element of the cause of action) because they hope to get a judgment for "nominal damages" (e.g., $1) to prove a point. They typically end up losing money, sometimes a lot of money, to get that symbolic judgment. If that's the avenue you hope to pursue, start researching possible causes of action you might bring.
But a clerical error, corrected by your landlord and resulting in no economic loss? You're not going to win the lottery on this one.

