I was about to change my plan from 35 to 45 per month when I received a warning that if I switched I would not be able to switch back. Wondering how this can be the case when my current plan appears in the current line up? Not sure what to make of this.
I think the warning is telling you that If the plan you're currently in isn't available then you won't be able to switch back. Pay close attention to what the system says you'll gain and loose by switching. Overage rates may be different or evenings and weekends.