Oh, I see. You've not only not read the examples, but you genuinely don't grasp the concept of language usage.
Important to note that Costa, say Panini and Sandwiches, not Paninis and Sandwiches.
Er. Do you mean Nero? I didn't post a link from Costa. Excellent close reading skills you have there. I suppose they have one letter in common, so well done for recognising that. It's an 'O'. Congratulations 
The Nero menu items read as follows:
THIS PLANT BASED 'CHICKEN' ARRABBIATA PANINI
Seasoned THIS! ‘chicken’ pieces in a tomato ragu sauce, with chargrilled red chilli puree and spinach in a sourdough panini.
vegan
HAM & MOZZARELLA PANINI
Ham with mozzarella and Cheddar in a sourdough panini
info
curtain
MOZZARELLA & TOMATO PANINI
Mozzarella & vine ripened tomato with basil pesto in a sourdough panini
vegetarian
et cetera.
Quoting several examples of when it's used incorrectly doesn't make it right, no matter how mainstream the companies you refer to.
I see. So every company is wrong. Every menu is wrong. Every poster is wrong. But you, @hotdiggetydog , are right. No matter how every single other person and organisation in the Anglosphere uses the word, you are right because you say you are.
Got it. Enjoy living in your little world where everything is just exactly as you imagine it to be. Perhaps you are the Queen. That must be nice for you.