You can obtain free community support for example through stackoverflow, or also through the Symfony2 mailing list.
If you think you found a bug, please create a ticket in the bug tracker.
If you take code quality seriously, try out the new continuous inspection service.
scrutinizer-ci.com
The configuration is as easy as choosing a random secret string which we will be using for encrypting your data if you have requested this:
jms_payment_core:
secret: someS3cretP4ssw0rd
<jms-payment-core secret="someS3cretP4assw0rd" />
The different payment backends which are provided by additional bundles likely also require some form of configuration; please see their documentation.