Do you have a separate account that was deactivated? If you do, the only way to proceed is to reactivate that one.
Linked account cases are tricky, try to contact and fetch as much information as you can. Try to connect the dots. There could be many reasons, address, IP, contact details etc. Before you write any POA make sure you have found the exact root cause.
It’s linked accounts suspension,
It means you have another account,
If you are able to identify the other account, then it can be reinstated by removing linkage.
If the 2nd account is not known to you then it’s nearly impossible to get your selling privileges back.
I am sorry to hear that your Seller Account has been deactivated due to being linked to another account which may not be used to sell on the site.
When your account gets suspended due to being related to another seller account which may not be used to sell on the site, it means that Amazon detected that it shares some information with another storefront, which is currently suspended.
It could be anything - e-mail address, phone number, bank account, credit card, inventory, SKU patterns, IP address usage patterns…
The link could have been created without your knowledge - maybe an employee logged into your account using his own computer or device, which was also used to access another account. Or someone else’s credit card was entered only to pay for an order in the buyer side of your account.
In order to appeal a suspension like this, you will firstly need to find the exact cause of the link.
Whatever you decide to do, don’t open a new Seller Account to circumvent the suspension, otherwise you will kill your last chance of being able to get reinstated.
I have the same problem and account is still deactivated