Sharepoint services has stopped working, access denied message...

I share a calendar that I've set up under sharepoint services that has been working fine for nearly 3 years.

This is being accessed via Outlook, through Firefox or Internet Explorer, & an iphone app called SharePlus.

Friday morning it stopped working, giving an 'Access Denied' message when trying to make any changes to calendar, no matter what user (or permissions the user has).

I called Friday morning & was told another dept had to handle this & would call me back & even told me they 'escalated' the call.

Here it is, over three days later & I've heard NOTHING.

Called again this morning & was basically told the same thing, they 'escalated' my case & someone would be calling me back, again.

Anybody else having this problem and/or has come up with an answer?