I created a site which has premium membership and want users to pay for those memberships. I have installed commerce_sp on my site but I don't know how to configure it and use it.
When a member pay for a membership for 1 year, for example: Subscription validity: 2014-09-25 13:45:00
but I don't know why, when I check this member again every once in a while. the Subscription validity has changed to: 2015-09-24 13:45:00.
And I check this member again tomorrow,the Subscription validity has changed again:2017-09-22 13:45:00.
I don't know why the subscription validity change again and again.
I was very confused, anybody know why?