This seems to be a common problem, they have an over-enthusiastic ‘spam filter’ (they said). I wrote direct to their Twitter account (@RedbubbleHelp) and got an automated response.
I then tried writing an email (firstname.lastname@example.org) and submitting a request on the their Help Centre page, from both of these I got an automated response saying the problem would be dealt with in four days. It wasn’t, but one of these methods seems to have worked because twelve days after I first wrote to them my Redbubble shop was back. I could login fine, everything works. I had this email from email@example.com
Redbubble Marketplace Integrity Team (Redbubble)
Jul 8, 16:04 PDT
Thank you for contacting Redbubble. Due to the high volume of requests at this time, we apologize for the delayed response. We understand that this is frustrating and we appreciate your patience.
Your account was caught in our spam filter and we’re pleased to say it has been reinstated. Again, we want to sincerely apologize for this mishap.
Redbubble Marketplace Integrity Team
I will also say that Redbubble drops the money from every sale straight into my account, so I didn’t lose any money over the suspension. If the account had disappeared for ever, it would just have been time wasted setting it all up.
Now if only I could work out how to get my Instagram account unblocked….