As someone who's been collecting for a while, I think there's an important distinction here that newer collectors may not know. In the trading card hobby, "Near Mint" does not mean perfect or free of print lines. Factory print lines are a manufacturing characteristic, not necessarily damage, and many pack-fresh Pokémon cards have them.
Stores typically use industry standards like TCGplayer's condition guide, where a Near Mint card can still have minor factory imperfections. Whether those print lines affect the value to a particular collector is a separate issue, especially if someone is hoping to grade the card.
If you're buying an expensive single, it's always a good idea to ask to inspect both the front and back under good lighting before purchasing. Every collector has different standards, and what one person considers acceptable, another may not. Neither of these takes make one person more of an "expert" than the other.
While I understand being disappointed if the print lines weren't noticed beforehand, I don't think it's fair to call a shop dishonest simply because a Near Mint card had factory print lines. Based on industry standards, those two things aren't mutually exclusive.
Plus, I've been to Blackbag, and there's a clear "all sales final" sign where they ring up your purchase. Most card stores have that policy. Because the market changes rapidly and cards can be damaged or altered or even swapped out after the customer walks out their door. I appreciate the policy because it enforces less risk to the rest of us as customers as well.
Blackbag is great and I would say they have always been really professional as well as fair in any pricing I've seen.
One bad review from an inexperienced buyer shouldn't change anyone's mind as far as checking out their awesome selection or participating in the game nights they host. read more