WPMU DEV on "Contact Form 7"

Hi @Raiden10,

Thank you for your question.

Have you tried using it as following.
[textarea textarea-172 5X5]

Textarea Option: (cols)x(rows)
Description: Columns (width) and rows (height) of text area.

Example:
[textarea your-message 40x10 "your message here ..."]

For more information, you can visit this page http://contactform7.com/text-fields/

Best Regards,