Hi I've fixed it now, if anyone is reading this thread and is having the same problem I had do a cold reset on your phone and then carry out the standard Group Divert.
1) Set group 1 to include all phones on your system
2) Group divert
Cold reset
System prgramming
System
Reset Options
Reset to Default
Best of luck, it's a shame that BT insist on you have a maintenace contract in place for such simple advise as this.
