To echo what @dutch and @jringo have already said - as the designer here, I have volunteered my time with no expectation of reimbursement, solely as a way for me to be involved in a project I heavily support. My reward comes from contributing personally to the project by using the skillset that I have to offer and seeing my work go out into the world - exactly why I do any design work.
This misunderstanding is very unfortunate - not to mention something that could very easily have been cleared up with a little transparency and discussion. Hopefully the individual involved will see this, or see our dedication to Gridcoin, and reconsider their opinion :)