Can she try phoning again? Sometimes different people handle customer service differently.
Also, did she call Whirlpool directly or the store she purchased it at?
If she bought it at Costco, they take most stuff back regardless of time.
Don't give up...
Escalate the call at Whirlpool and explain how they are giving themselves a bad name.
See if they have a facebook page and post your experience (or tell them you will...)
Thoreau said, 'A man is rich in proportion to the things he can leave alone.'