Okai, so found one guy that needed digital painting , i pmed him and he told me what i have to do

i worked on the pic for 4 hours strait and i showed him what i have made, he likes it and tell me to go on, i edit the pic 3 more hours !
after that i send it to him, and he likes it alot whit few changes in mind , he askes me to make few more jobs that he want to be done, i made them but he and his staff didnt like them, so they decide to stop working whit me and he gives me 500 forum gold for all the i have made when we first sad that the digital painting is going to cost 1k + he sad " i wont use that pic i cant give you more than 300"
!!Sry for my bad English its rly late now and i hardly keep my eyes open

so What do you think of it
1. he is right that i must not get the full price because they wont use the image or
2. im right because he sad he will buy it and its not my problem that he wont youse the pic and i must be fully paid

??
btw here is the pic that i made for 2 days
