RANT: why have a web page that is called "Update My Info" and it has fields but can't make changes?

I pay my water bill through NPW Services Corp...My account has my old number.  I click on “Update My Info”, and although my cursor (in Safari and Firefox...nope, I won’t check with IE) becomes an insert cursor in the field for my telephone number, I can’t modify the entry.  At the bottom of the page, there is text stating “...contact your Community Manager to update the information...”.  

WHY?  

No, why have a link and page called Update My Info if you can’t?  
  • Why have fields if you can’t change the data?

    Oh, let me throw one from work:  Why, after submitting info, do you put the error on the page and near the top instead of a pop-up or similar method to get the user’s attention that there’s an error?