I contacted mailchimp support because I have an issue with 'best sellers' pulling through sold out items - they told me its due to a duplicate store but theyre unable to delete it and have offered the advice below.

> 
> Issue of duplicate stores in your account. The work around for the
>  issue would be to use the API playground or a REST client to delete
>  the duplicate store in the account. Before doing this, we want to
>  stress that this deletion can not be undone and could potentially
>  affect the sending of ecommerce automations/emails that you have in
>  the account. That being said, I am aware that your account was running
>  into issues with accessing the playground earlier. If you would like
>  to delete the duplicate store from the account, we'd recommend using
>  the DELETE call for the duplicate store through a REST client and
>  would recommend doing this with the assistance of a developer if
>  needed. The endpoint that you'll want to use to delete that store from
>  the account is as follows:
>  <http://developer.mailchimp.com/documentation/mailchimp/reference/ecommerce/stores/#delete-delete_ecommerce_stores_store_id>
> 
> 
> If you would like to use the work around of deleting the store from
>  the account using the API, we'd recommend recreating the ecommerce
>  automations in your account to make sure that they are using the most
>  current and only instance of the store connected to MailChimp. While
>  the issue of having duplicate stores is unfortunate enough, I do see
>  how not being able to access the playground and having to use a REST
>  client/outside application only complicates the resolution to this
>  issue.
> 
> 
> 

From the answers they provided me with I can't figure out how to do it, I appreciate your help.