Help!!! with Grandparents rights

Hi all im in desperate need of advice regarding my granddaughter I keep asking but don't get any help..To cut it short my granddaughter was taken into foster care from her auntys due to behaviour problems social services said it was only way to get her help which I was mortified to hear..before this she used to stay with us once a month as I stayed in contact with her aunty...then I hurd last year she was going up for adoption I messaged her social worker to ask how she was and if I could see her he said no an that it was upto her adoptive parents and that was end of I've been looking for advice but no one ever gets back to me...my heart is broken and unable to get it out of my head that she must think I've abandoned her an wonder where I am why would they just stop her seeing the only family member on my side that bothers to want her in my life..if my health was better I'd have had her myself...I don't see my daughter anymore (mother of my grandchildren) we ended on bad terms... I would be grateful of any help and advice if there's anything I can do about this social services have not contacted me about the ins and outs of my granddaughters life it's just so wrong and unfair I thought it would be in the child's interest to be in contact with family...