I´m struggling with the sentence: "he said you called him a liar, but you would never call him like that."

I assume the first part can be written as: "onu yalancý diye adlandýrdýðýný söyledi"

how to construct the second part?

I´m not going to attempt to help with the Turkish - but I can correct the English!

 "he said you called him a liar, but you would never call him that."  (no ´like´

My attempt as a beginner learning all by myself:

"Onun yalancýyý seslendim dedi, ama hiçbir zaman seslenmesen ki."

Please wait for the correct translation by more advanced speakers. This is only a beginner´s try. Thanks.

"Onu yalancý diye adlandýrdýðýný söyledi ama sen onu asla/hiç bu þekilde adlandýrmazsýn."

Instead of "bu þekilde" you can use "böyle" as well.

It is a very long literal translation.

If you try to say it Turkish way it may become something like this:

Ona "yalancýsýn" demiþsin ama (bence) sen hiç öyle bir þey demezsin.

or a little bit shorter:

Ona yalancý demiþsin ama (bence) sen hiç öyle bir þey demezsin.