One of the 1st things I learnt in MA (Martial Arts) is respect; respect for fellow practitioners, respect for other arts, respect for your teacher.
This person is certainly not showing you respect.
There are 2 ways to sort this out, the MA way, and the 'other' way.
The MA way is to get/win his respect. This depends on your actual skills and capability. You do JuJitsu, he does TKD. I could safely say that most striking arts do not know how to deal with a grappling art like JJ/Judo where throws and locks are used, unless they have trained for it. If you have the skill (obviously you have, as you have thrown him), evade the strikes , step in and deliver a throw that causes a hard landing. For someone not trained in breaking a fall, this will take the wind out of him (or worse), then quickly follow with a lock to submit him. At that point ask for an apology, or continue to apply pressure and show that you're in control.
You should be able to win his respect or that of the rest of the dojo. What happens next depends that person and the instructor. If the person is a true MA, he would show respect and stop the harassment. The instructor should also have a word with him to this effect.
If this doesn't happen, then as others has said, leave this dojo/class. It's obvious that the instructor is not a Martial Artist,.. and they are discrediting the art of TKD.
The non-Martial way, and the more common sense way, is to leave the class for the same reasons above.