Folks, on Saturday I purchased a Sony A6000 camera from Jessops. Since then, several varied attempts to claim the due cashback on the Sony website have been unsuccessful. The following message is highlighted as the reason the claim is not being accepted:

Please check the following error(s):

• Invalid file(s). Only pdf,png and jpg files are accepted and file names can only contain a dot just before the extension. Please upload file(s) again.
• Invalid file(s). Only pdf,png and jpg files are accepted and file names can only contain a dot just before the extension. Please upload file(s) again.

As required, I attached photographs of the cash register sale receipt and the serial no on the camera both in png and jpg formats but thus far no joy and only receipt of "error" notifications.

Can somebody help and actually tell me how I can rectify this problem of "Invalid files."

Many Thanks

Derek