PIP initial assessment delays?

Hi I’m just checking if anyone else is experiencing a delay with the initial assessment? We made a call back in early April, we received a text to say the DWP would send out an assessment form. 
We haven’t received the form, the text was sent on the 11th April. I’ve tried ringing numerous times and put on hold for over 15 minutes after which time I give up waiting and hang up.

Has anybody else experienced the same with claiming PIP?