For any future users with same problem. The Web Toffee guys helped me out and showed me that I had to change the date formula of the CSV file so that the year doesn’t keep bouncing back to YY. For some spreadsheets (i.e the one I was using) the formula will be YY by default. It should be YYYY so just alter the formula of the year cell in your CSV file. It’s really easy to do, just Google it.
Or just use the example CSV file they give you in the plug in.