You can upgrade your plan for the upcoming cycle. The plan upgrade will not take effect until the next cycle begins on the 5th of the following month, which is when payment for your new plan will be made. 

If you'd like to add data immediately because you've used your allotted amount, you will be able to upgrade your plan in the Wing app (Download for iPhone or Android) or Wing Dashboard very soon. For the time being, you can request this via chat, or by calling 1-818-722-1441. 

You will simply pay the difference between your current plan and the higher GB plan you choose. It will go into effect immediately.

Your billing cycle will remain the same (every 5th of the month). The data cycle may vary depending on your specific plan.