Why did the man call two weeks ago?

W: You’ve reached Liaison Wireless. This is Mary. How may I be of assistance?
M: Hello. This is Robby Paulson. l called two weeks ago to report a billing error. I only used half of the minutes on my cell phone plan last month, but was still charged a fee for exceeding my limit. An agent informed me that the problem would be corrected. However, my last billing statement still had the incorrect amount.
W: I apologize for the confusion. I have your records here with me, and they show that we found the error and that you were issued credit. It will be reflected on your billing statement for March.