I have heard ´haydi ya´. The ´ya´ means what in this format?

´ya´ in this case doesn´t mean anything. It could suggest some emphasis or frustration. It´s quite common like ´offff, ya´. Or like in English ´oh, yeah´

You say someone;

+ Haydi(or Hadi/ I use this), Let´s go.

- No, I don´t want.

+ Hadi yaaaa ("ya"). Plsss. I want go. Pls

I can´t tell it but We use it like this