How do I display the name of the Appointments+ service in the MarketPress shopping cart?

Both Appointments+ and MarketPress are installed and working.

I really need the name of the service displayed in the shopping cart.

It now says Appointment: 21 (October 10 2013 07:00)

The 21 is just an increment number, I’d like to replace that with the name of the service.

Where do I start? Thank you.