Go to your auto attendant and look for “Transfer to a Phone Number” or “Dial by Extension” options and those use the Transfer audio file detail and look to see what it says.
If it does say Transfer.wav and not the double wav then assign it to a different audio file. Save. Then go back and assign it back to transfer.wav. save. Then test
If that doesn’t work then try this:
log into CLI and do this:
UCAS15#copy cflash aa/prompts/transfer.wav cflash aa/prompts/transfer2.wav
Then go into the AA menu and assign it to the transfer2.wav and see if it fixes the problem.