|"it's a land line business phone. and it sounds the "tone" about 10 times a day"|
The phone must have some sort of storage for messages & apparently none have ever been deleted. Try clearing out the old messages. If you don't know how, try reading the manual. If you don't have the manual, try searching google using the make/model of the phone. Either that or ask one of your coworkers who knows what they're doing to help you.