Ferns N Petals — Unknown Sender's Name

I received a courier from Blue Dart sent by Ferns N Petals. It was addressed to my wife and contained a dry cake. We both don't know who sent it and the box doesn't have any mention of the sender's name. I called FNP's customer care and the one who answered my call was a lady who told me that they too don't have any sender's information. Even on the box, in the place of the sender's name, two dots are present. Then, I emailed them and they replied that they cannot reveal the sender's name due to their company's policy. Again, the next day, I called the customer care and the person on the call told me that they cannot access any information with sender's email address. It was no use to contact them. The order ID is [protected].

I would like to know what actions can be taken against them and how I can come to know about the sender's name or any other relevant information.