If you sell subscriptions with Whole Season or Single Payment SKUs, members with zero box credits probably owe money. Whole season payers should have a paid credit count equal to the remaining delivery weeks in the season; Single Payment payers will need to Resubscribe and purchase additional credits.
Recurring billing SKU payers, either per delivery or larger billing units, must have a credit card on file and they will be billed when their paid credit count is zero at the next order deadline.
From the Customers & Partners / CSA Subscriptions / Check Payments Due tab (left green menu) you can view all subscriptions awaiting payment. Drill down to the member cash account--to see the actual balance due--via the $ to the left of the member's name.
From the Customers & Partners / CSA Members / Balance Due tab you can see all monies owed you in the cash account column, amounts due in red. To drill down to the member cash account click on the amount.