Now Strangulate is a problem but most dks dont use it intelligently, by wasting it while they still got distance. Plus none of them are sneaky, probably cause they have been told they dominate at this level. So they ride straight for you and death grip you in. Even if they do get it off, which it should get eaten by grounding, you jsut FS and GW away. If you think for any reason they will open with strangulate then drop totems and switch to GW, you can out run them for the full duration and they cant stop you.
Glyph of Stoneclaw totem will take out the dmg they get off after Death grip
Heart strike and Chains are pretty much taken out by GW cause with FS on them they move slower then you and a DK that isnt in melee isnt that strong.
If you cant seem to shake them then as I said in my write up, drop earthbind which will remove the glyphed heart strike and chains completely and make you immune to them for 5 sec while slowing them further.
Mind freeze don't mean anything, you shouldn't really be casting anything and if you are then you def shouldn't be doing in melee range of them
The point is that with dks is that you can try and go toe to toe with them while they beat you cause even in BiS gear they wear plate and have better abilities for it, or you can kite kill them and rely on the fact that they have very little ability to deal with kiting. Thats why they do well in 80 pvp till you hit about 1850. Before that its easy to kill people that think that they will burst you down first. When you get above that people realize that the buttons next to the dmg ones, that make you not able to hit them, that those work. and then you stand around a lot while people shoot shit at you, or in a like 3 minute stunlock, and yes it happens, trust me I had a rogue in season 5 stunlock me for over 3 min and when I wasn't in stun he was stealthed.