Starting new value plan before the end of the month? | 7-Eleven Rates and Plans | Consumer forum

I read in a post from 2013 that it's possible to start a new value plan before the end of the month (by cancelling the old plan and choosing a new one). However, I don't seem to be able to do this. My minutes for my current plan are up. But when I try to cancel the plan it says the removal will take place at the end of the plan's 30-day period.

https://www.speakoutwireless.ca/speak/7-eleven-rates-and-plans/monthly-plan-going-over-minutes-switching-to-btm/

Have things changed since 2013? That would be too bad! I don't want to be stuck with calls for 25c/min...

Thanks in advance!