SimpliSafe monthly plan upgrade

Hi,

I want to upgrade my monthly plan from standard to interactive. But I cannot figure out how to do so from the Control Panel.  Do I need to call customer service?

Secondly my current standard plan price is 14.99 pm. The latest prices for standard & interactive plans are 17.99 pm & 27.99 pm. If I upgrade & downgrade again, will I get new standard price of 17.99 pm?