I am sorry to hear that you have had trouble with your gallery images displaying.
If the header/gallery image you submitted with a listing is showing up in the header image area and not the gallery image area, it is indicative that eBay was unable to make a copy of the image for display in the gallery for some reason. You should be able to correct this problem in any listings that are affected using the eBay tool here.
As for the support form, there is an intermittent issue with the support case form that we are aware of. When the form fails to submit, it provides an email address you can use to contact our support team directly. Our engineers are aware of this issue and are working towards a solution. Apologies for any inconvenience this may have caused.