Looking for true management of Member Areas

When will Squarespace allow site admins to manage and edit memberships? There are situations where we have individuals wanting to pay for memberships in person. We are unable to take their payment because we are unable to add them to that membership manually. This has cost us multiple memberships. I also need all memberships to end on 12/31. I cannot edit membership due to Squarespace's inability to truly manage memberships. I must go and cancel all memberships on that date. I have to do this one by one. We at times have 70+ memberships. Squarespace states they want simplicity for member areas and provide no solutions. Squarespace's failure to provide true management tools is forcing me to look at alternative platforms for clients. Does anyone know a workaround or a better way to do the aforementioned tasks?