Hi,
I’m sorry that the widget is not displaying well in your website. The widget is created to be self supporting however certain theme can interfere with how it displays.
Please send me the link to your website and I can have a look to see what is causing the issue.
If you wish to add additional CSS classes (e.g. for a container class) then you can do this using javascript.
Just so you are aware, the widget does have it own stylesheet schema see the file: business-contact-widget.min.css.
In future, when reviewing plugin and themes on WordPress I recommend you open a support request and allow time for issues to be resolved, before submitting poor reviews.
Regards,
Alex