Is this bait-and-switch? (National Bookstore)

So for context kahapon pumunta me sa NBS kasi bibili ako sana ng gamit para sa group project when I saw na meron sila 1 peso school supply deal for every 99 pesos spent. And one of those items was yung 20 pack box na Platinum brush pens, approximately worth almost 300 php, kasama siya sa 1 peso school supply deal, as in clearly indicated talaga na kasama siya sa sale. So kukunin ko sana when this woman stopped me at tsaka sinabihan ako na "wait muna mhie, magpipicture raw yung saleslady yung display". Yung unang assumption ko was that, "Ay, baka customer siya na pinagsabihan din na huwag muna" kasi hindi siya nakauniform na para NBS, nakacivilian lang siya, and walang ID(as far as i remember).

So I waited maybe mga 20 seconds habang nagpipicture yung saleslady, and then pagkatapos, kukunin ko sana isang box ng brush pens. Mind you, there were 4 boxes of the same item na nakadisplay. And then yung saleslady and the woman na nakacivilian, ginsnatch nila, as in literal na snatch nila yung apat na boxes ng brush pens, (they were holding two boxes each). Yung nakita ko was that yung babae na nakacivilian, dinala niya pabalik yung dalawang boxes ng brush pens that she was holding, then yung saleslady na isa, di ko na nakita, so ill assume that she went behind me.

And then sinabihan ako na "Sorry bhie, someone already owns this." Like??? You made me wait while "nagpipicture" yung saleslady and once I showed clear intent na kukunin ko yung brush pens, you snatched it and youre telling me that someone already owns it? If so, bakit nasa sayo yung box instead of the buyer that you claim owns these boxes? And why did you display it (as in meron talaga sign with the product photo and 1 peso price tag) and immediately bring it back to the storage room? To be honest, I felt like I was lied and tricked to, like nakakainis. So much so to the point na I didnt buy anything from NBS and went somewhere else to get my supplies.

One of the reasons why I'm writing this rn is bc arts student ako. And when I came across the sale, yung una na naisip ko was, I could share this to my classmates na hindi nakakabili ng art supplies. I could just come in, buy a book na tag99, and then get that art supply that I can share to others. Pero experiencing that, di talaga masaya.

To those working sa NBS or similar na stores, is this common or standard practice? Do you normally take pictures of displays during opening hours and then take them back in storage? Do you think this happened bc high value item yung nakadisplay? Or I was just really unlucky at that time? I am so confused rn so helps :<