External DID phone number instead of internal Extension

[Sam2009]

Hi all
I have OXO R 7.1 and Omnivista 4760
and connect BRI Trunks ,and configure DID & public Dialing plan as example:
(external trunk Number ) 01121493041 ---> (internal user Number) 2822


But In Accounting report , I find in Extension field the external trunk number instead of internal extension Number

For example
Incoming Call Thursday, May 12, 2016
Date/Hour Extension Name Called Number
5/11/16 2:56:01 PM 2811 IT Support 0112316553
5/11/16 2:54:50 PM 01121493041 IT Development2 0115133174
5/11/16 2:50:06 PM 01121499545 Exams-Direct 01151598920
5/11/16 2:49:03 PM 01121493041 IT Development2 0116132411
5/11/16 2:47:49 PM 2851 PR 0115127617


could any one advice us, what I have to do or configure ??
thanks