I learned a few lessons when I bought a Samsung 75" curved television for my 95 year-old father, last year.
The customer (at least in the US State of California) is entitled to test such products, in-store, before making payment, and can request the selection of an alternate product to meet their satisfaction.
NEVER take delivery on any video display device without FIRST testing the unit, in-store, and verifying all functional aspects of the product.
Monitors are subject to dead pixels, obviously; and, particularly in the case of curved displays, they are extremely prone to breakage of the LDC/OLED sandwich--especially in the top corners.
In the case of my father's present, I tested through 5 damaged televisions before finding one that met my quality standards. That saved them from dealing with 5 irate customers. They should consider it to be free QC services, and an enhancement of their customer perception, quite frankly.
The guy at the store was somewhat pissed-off about my "pickiness"; but I reminded him that HE was being paid for his time, while I was not; and that it was me who was going to be paying money--he could consider this to be my right to a "test drive".