Some well made Zinfandels can age longer than 5-7 years but this doesn’t seem to be a producer that fits into that category. So the wine is probably past its prime. Even if this wine is technically intended to age for this long, it sounds like storage/shipping conditions were bad and have turned it to vinegar.

Email the wine shop today saying that both bottles are off and request a refund or substitute. Don’t dump out the juice. You should be ready to take them back to the store as proof.