We only integrate with Stripe and Paypal so you're best to contact these companies directly if you have particular questions.
However, one common question was how to see if a student has paid/failed to pay their subscription in either of these systems.
See how you might use these reports:
You're able to see on Stripe where payments have failed from the Payments dashboard.
Paypal explain their recurring payments dashbaord in one of their help documents here
You can use these reports to quickly see whether accounts are active or cancelled.