Excel Data Tracking from Sheet to sheet

I have an Excel workbook that has two sheets. The one sheet changes as we enter new information in the same cells each time we receive a call. The other sheet was made to track the information logged in the 1st sheet. However I want to keep the previous information put in sheet one on the tracking sheet when we change the 1st sheet. 

I have the formula as an IF function and it works based on the tracking number. 

Example:

Call One

Tracking # A1   Sheet 1 shows Caller Name as John and Sheet 2 then shows Callers name as John 

Call two 

Tracking # (Changed to) A2 so on sheet 2 the new caller would be put in row 2. 

At this time when we enter the second caller because the cells are not changing it deletes the saved information from row 1 on sheet 2.