Alex, Users are getting charged more than once on the same product even though they already have active subscription to the same product. Also, The product has "Disallow ordering of this product if user has" but it has still charged users again and again. What could be the issue?
First of all, that option("Disallow ordering of this product if user has") is for signup form only. aMember doesn't check it when process recurring payments. In order to check this issue I need access to your aMember Control Panel and exact example of user who have this issue.
I had a problem similar to this on one of my sites... It turned out that it was a conflict in settings in the credit card module. Essentially, the credit card module was set to retry failed billing attempts on days 1,2 and 5 after a billing failure. But the payment processor uses the latest card details for all payment attempts. So what was happening was that when cards failed, the member set up a new subscription, and then the old one kicked back into life on the rebill attempt because of the new card details. So, in your case, take a look at the accounts with duplicate billing and see if you can tie the payments back to subscription invoices. That may give you a clue as to what is going on, Cheers Rob
@jwmmarketing please contact us in helpdesk ( https://www.amember.com/support ) and we will troubleshoot your issue.