Creating a duplicate GBP while the main one is suspended is a major violation of Google TOS and will make your appeals fail regardless of what you are doing and how compelling your case is. You NEED to delete any duplicate profile before appealing the old one. If you did not create it, claim it from the front end and delete it before attempting anything else.
Using city in the business name is also against Google TOS
https://support.google.com/business/answer/3038177?hl=en#zippy=,chains-brands:~:text=Guidelines for chains, departments & individual practitioners unless it is part of the business trading name and they can justify it.
It is not because others are doing something and because it works that you should replicate it. They might get slapped at some point once the system catches up.
Stefan made some solid recommendations regarding the paperwork to provide. Just make sure the NAP using on the GBP profile is consistent on all documents, and get your citations in order too (at least the main ones).
Now that you seem to have received 2 refusals from Google, the good thing is you should have a direct line with Google staff. Your client should have received a refusal email that states the "redress options" if located in EU and other redress options.
This email always comes from a non no-reply address so you have 1 or maybe max 2 last remaining attempts to email them and save your profile.
Make sure you:
- Delete the duplicate listing. Attempting anything else is a waste of both you and Google's time and they will play deaf.
- Address any violations left by carefully reviewing the profile against their TOS
- Prepare all the documents (as explained above by Stefan) and put them into a public G drive folder. Make sure the NAP is consistent.
- Follow up through that email and explain to them that you are requesting a reconsideration, explain what you have fixed and which violations you have addressed, link your G Drive stating that this is a legitimate business and kindly request a review.
If everything is done right it should work. If it fails, it means you still have violations left on the profile. You might be able to send another email back but at some point they will just ghost you.
Your only available option will then be the GBP help forum and pray that some product expert escalate your case.
Hope it helps.