IF command not working in batch file

So I have this bit from a script of batch code I'm writing:

set Line=Say

:IsLineSay
IF /I %Line%==Say goto DoTheSay
set Line=hi
goto IsLineSay

:DoTheSay
cls
echo hi
pause

But whenever I run it it closes at the IF /I %Line%==Say goto DoTheSay part. It doesn't give an error message or anything, just quits the batch file.

Why is this happening and any ideas on how to fix it? I have absolutely no idea why this happens. Thanks in advance!