What does it say in your confirmation mail (and the attached invoice) and in your Eurail account, in the order overview?

It says 15 travel days. In the invoice it says: Validity 15 days.

Should I seek refund and order a pass. The payment says: “This Pass is fully refundable without a fee … Submit your request before the first travel day of the Pass”

It would not make any sense for eurail to sell 15 travel for 15 days validity. Nobody travels every day on a train.

I am confused. I bought the “15 days in two months” pass” which I thought would allow me to choose 15 travel days over two months from the start date”.

Please advise

If your pass is fully refundable, then do go ahead, request a refund (can be done online) and buy a new pass. Select the "15 days within 2 months” pass rather than the "15 days” pass. You now have the latter but you want the former.

You'd be surprised how many people buy a consecutive pass.