waiting time

Hi, I have lived in Spain for ten years now. I am 67 years old and am on DLA. I received a form January 2017 asking if I wanted to claim PIP. I said yes, answered the questions and filled in the form when it arrived (late February). I heard nothing for a while then told I had to attend a medical in Albacete which is over an hours drive from where I live. It was a cursary interview lasting maybe fifteen minutes on top of which they would not allow my interpreter into the interview. This was in September. I was informed in October that the DWP had received the transcribe of the interview and would be making a decision in due course. I phoned in January this year to see what was happening as we sometimes have post go missing. I was told it was still in the hands of the decision makers. Since then nothing. Is this usual to wait for so long? If I had not been claiming DLA I would be sitting with no benefit which I need to live a normal life. Was it right that I should have been denied an interpreter? Anything I can do or do I sit back and wait? Sorry this is so long winded. Andyroo