We can't practically maintain official payment gateways for all counties for a few main reasons:
- FOSSBilling is maintained by a very small group of contributors who do so in their free time with no pay, so we can't indefinitely scale the scope and official integrations while being able to provide a reasonable guarantee that said integration will function as intended.
- We don't have team members in all countries which can be prohibitive when trying to sign up for services. Our regular contributors are primarily based out of the UK and US with less frequent contributions coming from the Netherlands, Switzerland, and Turkey.
- We prefer to keep the official list down to just services we have access to test / update if needed. We actually recently removed 2 server managers and 5 payment gateways from the core software as they were either known broken or untested without any updates in many years.
If you're a developer, it shouldn't be too complicated to create an integration for most services and we'd be happy to provide insight into the underlying systems where needed, but at this time there aren't any plans to extend the existing support.