Public Mobile does not offer this service. I have a free app called "youmail" that handles all my voicemails and it has a trascription service. Its really slick and easy to set up. Not sure if its supports your phone but worth checking out.
Not sure if they enabled the correct OCN settings or not... I just tried youmail again today and it works! I have a plan that has free calling to the usa and canada not sure if that made a difference... It working for me as of today!
