This happened to me one year
Horrible, but so not worth the risk of trying to cook/eat.
My Db told me a whole stretch of horror stories he'd picked up on the grapevine this year about most turkeys being processed and prepped in early Nov and the fresh ones then sitting around for two months before sale often in dodgy transfer situations, which is why so many are going off before Christmas day, even when sold well within their use dates. He warned the family to buy frozen or to choose another fresh meat instead, and I admit it's put me right off turkey.