This page explains how to re-activate your account if it has been banned or de-activated by Instagram.
When your account is disabled/banned with Instagram, you can recover the account using this form.
The entire process roughly takes 3 - 7 days as Instagram gets a lot of requests through this form.
Within the template questionnaire there will be a question regarding for what reason your account may have been suspended/blocked. You can answer something related to this:
“I think my account was disabled by mistake. Please recover my Instagram account. I do not purposely ignore Instagram terms and rules”.
Instagram may also ask you to send a photo or government ID to verify that you indeed own the Instagram account. Please note that for business accounts Instagram may also ask for a bill or a bank statement featuring the business name.
Once the form is completed and sent you will hear back a reply back in your associated email address.