fizzy coke

I don't know why exactly, but with the last several 12-packs of Cherry Coke Zero I've had, every single can has been extremely fizzy.  I know they carbonate it, but the can hasn't been tampered with in any way (i.e. shaking, dropping) and while it doesn't rush out right away, it slowly builds up after I open the can.  If I'm not attentive it can head up and out of the can itself.

Once it dies down, the rest of the coke predictably tastes flat.

This is really annoying and I wish it would stop.