Old feedburner account is still posting for new website

[gary....@recommind.net]

A feedburner account for the corporation I work was created by either a contractor of freelancer for their original blog in 2010. There is no record anywhere of who these people were or what email they used to create the account for blog.recommind.com -- but when we switched to WordPress CMS people internally -- and I am sure externally -- began to get RSS email posts not just from the blog but all new pages from recommind.com

The few people that still remain from that time were not involved, and all attempts at Google account recovery have failed.  We now have a Google Business account -- recommind.net

From this discussion group, there are oothers that experienced the same issue, but I don't see a resolution. There seems no way to delete this old FeedBurner account: blog.recommind.com We don't use the subdomain anymore -- different site, company, etc. 

Any new source of assistance with this problem?