correct or not?

[Tukanja]

Me:'Hey how's happened you've come on foot here? Has your car broken down? Have you read my message. If so why haven't you replied?'

Friend:' OK, OK, let me say a word.'

Me:'Go on then.I'm listening.'

[ETutor]

Me: “Hey, why did you walk here? Did your car break down? Did you see my message? And if so, why didn’t you reply?”

Friend: “Ok, Ok, let me get a word in!”

Me: “Go on, then. I’m listening”

[Tukanja]

Thanks

[Tukanja]

I am very sorry ET but I must ask the next question as well

Me:'Hey how's happened you've come on foot here? Has your car broken down? Have you read my message. If so why haven't you replied?'

Friend:' OK, OK, let me say a word.'

Me:'Go on then.I'm listening.'

Is it possible to say this this way

Me:'Hey why you've been walking to here? Did your car break down? Had you read my message? If so why didn't you reply?
Friend:"OK, OK, let me get a word in!'

Is there a need of using the Past Perfect (Had you read) if the sentence is followed by another sentence which is a consequence of the first one?

Also I think I saw sometimes

Why you walking to here? (Why you have been walking to here)
Is it possible to use the Present Participle of the verb (walking) in such sentences? If so is it informal English then?

Ah, a lot of questions at once.