I too had the same issues. After half a day I found a post on FAQ. Go to "Family Tree" tab and click on "Summary". Here you will see the option to delete.
I have done this but now can't load a new gedcom in. While it uploads it, an error comes back:-
"There was some problem with the upload file so unable to publish family tree."
I have tried several times and a different gedcom but still no luck. I may try again in a few days.