Quining Qualia - Daniel Dennett. Why this Philosopher is Denying the Existence of Qualia?

I got a read onto the Daniel Dennett article's and watched several videos to get an understanding of it.

If I understand correctly, then qualia are the perceptual and sensitive states of an individual. Those states answer to question "What do I feel?". For example, if I put my hand into the warm water, my receptors will say "Don't you dare to put your hand into the warm water.", because I will feel PAIN. I think that this definition is suggesting that to acces qualia, you must have something intermediary. In that case, a possible intermediary shall be the body (more specifically the receptors itselves, which send stimuli to the brain, which does whatever it does to tell "this is PAIN") and memory ("I can remember that, in the past, I put my hand in a warm water, and I feel pain"). Still, Dennett is denying qualia, but I don't understand why.

Let's get to one of his intuition pumps about Chase and Sanborn. This guys were employees for ten years in a coffee shop. The last time they tasted the coffee, they observed something changed.
1. Because of his change of receptors, Chase feels a different taste for the coffee, which is worse than before.
2. Sanborn, on the other hand, lost his memories. He doesn't remember how the taste of the first drinked coffee had been. Something is slightly of with the coffee that he had tasted.

So, from what I understand here, Dennett is trying to say that qualia is changing. I think he is right, because qualia comes into many different forms, which can make the problem more complicated. But, this still doesn't refute the existence of qualia. What changed had Chase and Sanborn experienced is for the intermediary, but not for qualia. Chase changed his receptors and Sanborn changed his memory, so they get a different qualia

I got something wrong? Any thoughts?