Custom Shipping Provider and Services - Service Labels

I have created a custom shipping provider and associated services using the sample code on:

docs.sitefinity.com/for-developers-create-a-custom-shipping-provider-field

I have created a new shipping method using the new custom shipping provider. In my site, I can now check out and select shipping services defined for the new custom shipping provider and I'm getting shipping charges calculated as expected, however in the front-end, the services are displaying as "SAMPLE_SERVICE_01" and "SAMPLE_SERVICE_02".

How do I change those shipping service option labels to something like "Ground" and "Air"?

I have tried going into site administration under Ecommerce | Shipping Methods and editing the shipping method defined to use the new custom shipping provider and clicking on the Properties link for each of the defined services. Changing the Service name, Service code and Service description don't seem to have any effect on the labels for those services in the front-end checkout screen.