Have you tried making the change on a different device and/or browser?

Hi ​@steveyxe2 we can change it for you. The $0 25 GB add-on you have on that line will drop upon plan change, please confirm if you’d like to proceed and what perk you’d like with the plan, thank you!

Thanks! I'd like the rollover perk. It's for the line that ends in 9070. 

Ok ​@steveyxe2 the $44 100 GB plan is active with the $0 Rollover Data perk, please restart your phone when you get a chance to make sure the changes come into effect.

As we've changed the plan mid bill cycle, the data will be prorated. Here is more information on that https://www.koodomobile.com/en/help/proration

The auto-pay discount will come into effect starting next bill cycle.