AnsPress shortcode cannot be nested.
There’s a lot to this question. Did you have a written agreement with the owner? Did the owner give you the specifications or did you create them independently. Trademark is not the issue. There is an issue of copyright potentially. If you had an agreement this document would control. If you did not have an agreement then we need to look to past dealings or industry standards. You may have a legal claim against the owner and need to speak to an attorney