Update/removal of Joomla selling platform

We have a problem accessing Joomla platform since the employee setting up the selling platform left the company and Admin login/password to not give us access to the site. We have expired products on the selling platform and we want to remove/delete the Joomla store.
We do not know how to do it ourselves, therefore we are looking for someone that can do it for us.

Let me know if you can recommend someone. We are located in Jersey City/Newark area,

Thanks and regards
Jetwajsnacks/Snacktree International
Christian Reinhardt
Controller