Did your activity lead to h4ns getting their money from Bestmaster or a 210 refund by June 30 2019?
My activity did not lead to a 210 refund by June 30 2019 as h4ns wanted to assist him further until
September 3rd.
You seems have no problem in showing emails, so show email where he said that he does not want refund yet, instead, he wants you to continue with the case.
Don't saying that he wants it back
is saying that he does not want it back!

Then show email from September where you said you are closing support tickets and that he will be refunded.
We had the agreement that I will assist him and recover his funds from Bestmaster or return his 210 by 30 June 2019
Does not want my assistance anymore means closing his support tickets and paying him back.
You should've kept your agreement.