This looks like a formatted print file complete with printer control codes.
We may need to convert the control characters to text before running a textual search. Also, we usually process an open ended list of files in "while" loop which also stops the script breaking if filenames contain space characters.
Try

ls -1d invALL.06* | while read FILENAME
do
       # sed -n l (character ell) converts control characters to text 
       count=`sed -n l "${FILENAME}" | grep -c 'Invoice Total'` 
       echo "${FILENAME} has ${count} Invoice Totals" 
done