One of the main questions one should ask a hair vendor or manufacturer before purchasing hair.
“After care” means that if anything wrong happens to the purchased hair after normal use, the vendor will offer such warranties as a refund, free items, repairs, and or discounts. Hair can be very expensive and should perform as it is advertised.
What is “normal use?” Normal use is regular hair wear, regular washing and conditioning, and styling of the hair. All hair that is not raw hair is processed, meaning that it goes through a serious of steps after cleaning to either form a certain curl or wave, or become very soft and shiny.
So Yes, the normal shine may wear off, but if your hair is simply goes from a deep wave to completely straight, chances are the factory did not process it well and you should get your money back.
I am very weary of places that are don’t offer any refunds. Exchanges are ok, but not when most of the hair will need to be exchanged, so it is really good to sample hair before going all in.