Hair in Magnum Ice-Cream

A few weeks ago, I bought a Magnum ice cream and found a strand of hair in it. I reported the issue to Magnum , and they collected the hair sample for testing. Two weeks later, they emailed me claiming that the sample I originally sent and the one they tested were different—suggesting that I had sent them my own beard. This is completely absurd. Now, they are dismissing my complaint as invalid and offering me a voucher for a new ice cream. My main concerns are: how did they conclude that I sent my own beard, what happened to the original sample I provided, and who told them I even have a beard?