Membership 2 last membership

Hello,
I'm using Membership 2 and my client can subscribe to more than one package, but i need to know witch one is the last he subscribe too, and show him the start and the end date of his subscription.

i'm using wordpress, i tried the function membership_get_expire_date() but it telling me Fatal error: Call to undefined function membership_get_expire_date() in /h

Can you help me with that ? thank you !