YES, you need to contact IT first to get the IT Policy removed from your device. To check that the blank or 'default' IT Policy has been received, click on Options (icon) -> Security Options -> General Settings. Scroll down to the IT Policy Name.
After that has been done, and before having them fully remove you from the BES, see if you can disable the password. If no, then they changed the default policy and you'll have to follow steps on your own to remove the policy.
Oh, and 'BIS' stands for Blackberry Internet Service, which is a portal from your carriers website that allows you to set up personal email addresses for your BB (i.e, your @charter.net email can be sent to your device). Sprint's BIS site is here:
https://bis.na.blackberry.com/html?b...rint&locale=en