If not stated in divorce decree, who gets the mortgage escrow?

There is no determining factor, except if it is mentioned in the settlement agreement or Final Decree. If it was not mentioned in either, then it is left to whomever's name is on the mortgage. If joint, then notify the mortage company that you want both names on the refund check.

If both names are on the mortgage, the lender should issue any refund check jointly.

Without knowing the details of your divorce, and the decree, it isn't possible to answer your questions. If you had an attorney during your divorce, you need to contact him/her about your question. If you didn't, you need to contact an attorney about your options (allowing them to review your decree documents). I hope this information helps answer your question(s). ~ Kem Eyo