That’s pretty shitty. They’re probably talking internally about the fuse as if it’s some type of tamper seal. But fuses blow sometimes, they’re literally sacrificial. So somebody has told their support techs that anyone with that fuse blown has tampered with their battery and they’re just repeating that line to customers (some guilt of tampering, some innocent).
Or maybe you just got unlucky with a dumb support tech. If that’s widespread, they deserve to get sued.