Is there a time frame to receive a refund after filing a 1040x and never received a refund as an executor and daughter for the estate

As an executor and a daughter, I noticed my dad's tax account completed the forms incorrectly. I did file  an amended form but never received the monetary amount due to me.  I dont know if they mailed the check or refund to the his old address or the wrong address but I never received.  It has been beyond 7 years,  can I still ask for the refund?   I am not sure whether they received the 1040x or not.