The $20 UNLIMITED Data Plus option is only available on the $28 /mo Base Plan and +Phone Plan.
Step 1: Open the Circles.Life app, you will see Home.
Step 2: Under Add-on options, look for Unlimited Data.
Step 3: Slide off the Plus option UNLIMITED Data to the left to turn off.
Et voilà, you’re done!
Please note that the deactivation will take effect from the first day of the following month onward - meanwhile, the Plus option will still be available on your plan!