A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
I had the same problem and figured it out following these steps:
1- Click on the first cell on the spreadsheet
2- then go to Data » Sort.
3- Select "My list has headers;" sort by Columns; Sort on Values; Order A-Z, if your columns have a header (title)
(if you click the arrow down in columns you will see the heading of your columns)
4- Go to "options" and select either top to bottom, or side to side!
5- Press OK
The problem I was having is that I was not using the "options" button to select the direction of the page the text should be sorted. I usually do it Top to Bottom, not Side by Side.
Hope it helps.