My gut answer is that you have an agreement with Dillard's on the issue, a Debt Holder Right. Dillard's probably can not make you give up that Right without a Bankruptcy Filing, i.e. going to court.
If Dillard's were to Tender for DDT, they would have to anticipate holdouts. My guess is that you would remain on the Books as a holder of the debt, and perhaps there is a firm who might specialize in taking your debt off DDS books and funding it in something like TBills for a fee to Dillards
I say Dillard's can not hold a gun to your head and make you sell....that is until the Obama Socialist rewrite all the Commercial Law in this Country.