This works for me and i did helped with a guide for two of my friends in bangladesh, one in Australia, and three in USA to mention a few.
You ate likely going to get approved if you follow this little step.
Note: It works for me and i hope it does for you too.
Good luck
(1) Choose Novelty and T-shirt business.
Lots of people who have been rejected once run away from this. They think the T-shirt category is crowded already. No, the resaon for rejection isn't becaus of the category choosen.
(2) You can write anything in the organization name.
(3) Additional Information
Here, Amazon want to know the value you will add to her. So i suggest you write something enticing and irresistible. Write there you have experience with amaxon affiliate business even if you don't, write about your design skills even if you have no knowledge about shirt designing. Just write and tell amazon you've tried different design on several platform such as etyl, redbubble and tee-spring and you will be glad to show your professionalism on merch playform.
(4) Website (it's important and not optional of you want to get approved very fast)
Make sure you input your website as amazon will be glad to know you have social awareness. It is profittable if you can add an amazon niche site url, as it will help to fast track your approval
(5) Submit the application
(6) click on the contact us and copy the email address
(7) Send email with the subject "merch support"
With the email address you registered with, send a mail to the merch email address copied.
The body of the message is to tell them why you love amazon, why you love shopping on amazon and why uou will want to get on with merch
(8) Response from merch
You will get a mail from merch. Just ignore and keep checking for your approval mail.
It only took me three days to get approved with this method.
Good luck