It's probably sitting on someones desk, or maybe the person who got it retired in january's exodus...!
Just ring again to follow up, quoting your PPSN. As it's a form 12, you could call the PAYE helpline, they should be able to see whose workflow your stuff is in and maybe speed things up.
You won't get a cert to say your tax compliant but you should get a balancing statement if you haven't already.
thanks mandelbrot , tried calling this afternoon and till no answer....
Will try go online and request the balancing statement see if that comes to me ok.