I want to upgrade from Starter to Explorer as I was told (incorrectly) that webhooks and API was available on the Starter. It was corrected, I upgraded but had to pay the full $349...
When you upgrade from Starter to Explorer, you can receive a refund for your Starter plan payment. The refund typically reflects within 10 days.
You're correct that webhooks and HTTP API are Explorer plan features, not available on Starter. The Starter plan only allows using your own API keys for data enrichment tools, while HTTP API integration requires Explorer.
If you need further help with your refund, request human assistance by clicking on "Talk to a person."