Yes this is actually a basic purchase document that should be given without anyone asking especially if you buy electronic that costs thousands.
i also sometimes buy phone case, screen protector very cheap still they give me receipt. This i bought RM3600 , even when i asking they wont give me.
my problem is actually quite a small problem but i imagine if other ppl got bigger problem (bad batch in their device etc) , they might have hard time because their customer service never reply unless you keep ping them every 30mins.