If you have recently changed the price of one of your membership plans and have noticed that the new price is not effecting your existing members, this is because you can not change the member plan price on your existing members.
You should not change the settings in a member plan that has active members on it.
If you do, the members already on that plan do NOT get those new changes applied to them. A member's recurring information settings are written to their account at the moment of signing up so because of that, changes to a member plan after the fact will not affect them.
Instead to correct a member's billing situation, do the following:
* Create a new member plan with the correct billing terms (Edit Member Plan)
* Edit Member Details for each member
* Change them to the new (correct) plan
* Also set their "Renewal Date" to be the next time that they are to be billed on that new plan
* Press apply changes