Yes, data plans can be increased/decreased at any time with no penalties or fees.
To do this, launch your Scoutek app and go to the My Account section. Select the option to Change Data Plan at the top of your screen.
Please note, if you have reached your current data limit prior to the end of the billing cycle, and would like to avoid paying overages, simply upgrade your data plan, and you only pay the difference between the two. Also, if you realize you have not neared your current data limit prior to the end of the billing cycle, simply lower your data plan, and you will receive a credit for the difference in your account.