Basic Formula Not Subtracting/looking at Imported time Correctly

[jayclinton]

I am putting together a sheet that I will use daily. Columns A-F are imported from another program as is. This issue I am having is that the formula I wrote isn't looking at the minutes/seconds they way I thought it would. My formula:

=if(C5>$k$2,C5-$k$2,C5)

I highlighted the workbook to show the issue. In this example The data shows:

C5 is [00:47:25] K2 is [0:50:00] So my answer should k5 [00:47:25], but this isn't the case. It is trying to go into a negative. I don't understand why. I tried all different types of formats and cut & paste solutions from online, but to no avail.

Any help would be greatly appreciated.