Hi Shane
That is a very long time. I can't tell you why it is so long. Yours isn't the longest time someone has been waiting, but it's not far off. I assume that you have continued to be paid your PIP or you would have said something.
If you're still receiving your money, you could just sit it out and wait to hear from them, but you might want to ring the DWP and ask them when you might expect to hear. (I can understand if you don't want to make that call - but it's the only way to find out the reason for the delay).
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
