I want to see my grandson, miss him

My name is Kerry,  I had one child, a son Braidon who was 26 when he passed away.  This shattered my heart and my world.  My son had a 6 yo son when he died, his name is Cohen he is now 8.  When Braid was alive I would have Cohen stay with me every Friday or Saturday night, sometimes both so Braidon  and his partner could go out.  Quite often they would drop him at work with me (we owned a restaurant) so they could go to gym or to the movies etc.
After Braid passed away it was still the same with his ex partner.  Then one day it all changed for no reason.  She will not let me, my family or any of Braidons friends see him.  Not only has Cohen lost his father who he adored but he has lost everyone else who he loved all at once.  What must this poor child be thinking. 
I tried mediation, she would not respond so I have been to a lawyer, I was so happy, she said I would most likely be entitled to almost the same rights as a parent because I had so much to do with his upbringing.  Then the devistation, if it goes to court it will cost $30,000.  I was shattered again.
I have never been one to ask for help or handouts, but I miss my grandson so much and want him in our lives and I can’t find any other way to make this happen.  So I am asking for help! I know there are a lot of kind people in this world, if anyone can help I would be so grateful.
thankyou for taking the time to read my story and please share it.