The only thing to which you are entitled–by definition–is access to the source. It is your responsibility to verify what the source does.
The "getting paid" notion is off-topic and has nothing to do with the source being open. If I provide commercial support for someone and implement a solution using open source software, I am the one providing the support and I have no expectation that the original authors will hold my hand.
The "getting paid" notion is off-topic and has nothing to do with the source being open. If I provide commercial support for someone and implement a solution using open source software, I am the one providing the support and I have no expectation that the original authors will hold my hand.