"Poor pain relief after transplant"

My son had a kidney transplant and whilst he was on the infusion pump it kept the pain under control but unfortunately after the first day that was stopped and he was left crying and screaming in agony on several occasions which was not acceptable. The same thing happened with his brother who donated his kidney he was left with agonizing pains and nurses did not respond to our requests to help them, the pain nurses were apparently called on 1 particular day less than 2 days after surgery and when I arrived was told it had been 4 hrs since they'd been called and they still hadn't sorted his pain out. I am very disappointed with both of their treatments, leaving patients that have had surgery in so much pain as if they don't deserve to be comfortable. I am putting in a complaint to  PILS so that hopefully this won't happen to somebody else's relative. I don't know if the blame lies with the nursing staff on ward 17 or with the slowresponse of the pain management nurses but this ward was terrible for us compared to the ward my son was on prior to the transplant - the staff on that ward are amazing.