Locked Out Off Programming Bt Inspriation System

I have no idea what I ahve done to my system, while I was setting the system up I managed to lock ext 21 and disable ext 20. Both ext. have feature phones.

Ext 21 phone will only go to handsfree don't matter what button I press.

Ext 20 tells me programe refused when I try to access the system, not only that if I call Ext 21 it tells me that I am calling from the line I am using, and if I dial 0 it tells me it is invaled.

The other problem and its nothing to do with the above, because this has done it from when I first installed it 3 days ago. if I press line 1, 2, or 3, I get a dial tone but after I hang up I can't get a dial tone at all, I have to switch off the system then back on again. I can get incoming calls all the time, no problem there.

Can anyone help me.

regards

Darren