I filed an amended return last year and moved unexpectedly, the check was mailed to my old address and I never got it. What do I do?

I moved unexpectedly, when I checked the IRS website, it said that my amended return check was delivered, but to my old address. I cannot for the life of me get ahold of anybody to figure out if they can disburse me a new check and have it sent to my new permanent address. What do I do?