The mantra of consumer organisations in the Netherlands/European Union is different.
When you go into a store (brick and mortar or on the web).
You choose a product with certain specifications. And the small print on the box says X year warranty.
You put that product in your cart (real or IT), walk to the exit, pay the product and go home.
After a certain period the product no longer gives you xyz lumens (or ground coffee) when you push the button.
In Europe there is one party to address: the party that took your money.
EU legislators are aware that big corporations employ departments whose sole purpose is to wear you down.
That’s why the party that stepped in for the delivery of the product, must take care of the warranty of it.
They will have to offer you a deal to take away your grief. That can be a new product, or a new part (tail-cap).
Or a heavy discount on a new and improved version. Sometimes the warranty excludes the cost of labour.
When there are more bad reviews about a certain product, you even can address the department store directly.
They might have sold products to innocent customers while they knew that it were bad apples, so to speak.
Consumer organisations also preach: don’t under-estimate the power of social media.
You can suffer in silence while the CS dept of a big corporation gives you a run for your money.
It is more effective to start a hash-tag in which you share your experiences with innocent potential buyers.
Often such a complaint will get you a “transfer” from CS to Marketing (who is more worried about future sales).
Nothing is more damaging than a thruth that is different from the text in the brochure.
EDIT: if you had bought these from GB or BG or FT, you would have addressed GB or BG or FT.
So why don’t you address Walmart? They sold the lights to you, and took your money.