cdl340

I have a 2008 E350, and wishing to clean out the phone book and start new, however it is getting tiresome to do it one number at a time, the other issue is, i have duplicates of the same number. I attempted to go in the command function and reset, but it did not work. The numbers are still there, even when I erase the numbers and restart the program the numbers stay. Any idea what could be done, Thanks