As a commissioner, you are free to use the final product as any avatar, banner, etc. I highly appreciate being credited, but it is not necessary, as long as you don't take credit for it yourself.
After the commission has been paid for and the subject and specifications decided. I will send a WIP of the image so that any adjustments can be made before the final product is given to you. If you have any special requests (progress images, no background version, etc.), those files will be provided.
Refunds are not accepted past the invoice payment process. Please contact me additionally if there is a problem or issue you would like sorted out before paying.