Cancellation Procedure Unfair

Can you advise how i write a complaint to NOS as I have called all the lines and its only Portugese and I only speak English.

I have been to the NOS shop 5 times about the concern and they advise I speak to the number they give and again no one speak english.

I wrote in the complaint book in the NOS shop and they said they would call again it was a call from someone who could not communicate in english.

 just want to know how i communicate to NOS by email.