"Extremely poor"

My 11 yr old has been referred here Nov 4 2015 by his orthodontist and his regular dentist for urgent root canal on his adult front tooth as the nerve gas died and he is at risk of losing the front adult teeth involved ! It took over a month for us to receive a letter saying ring and make an appointment ! I rang to be told January 25 2016 so almost 8 was later for just a consultation when I queried another consultation when my son has 2 professional dentist referrals sent and X-rays I was told they would pull out the referral and ring me back which eventually they did by the dental management suite there dentists make there own decisions of treatment plan ahead and they don't take into account the two referrals beyond it justifies my child getting put on a list and there are 100s of children in the same boat as my child he's just one of many to them ! I felt concerned by the lack of regard to my son as a patient to say the least but I patiently waited for 25 Jan and to my shock the Friday evening before the dental hospital rang at 5.03 pm on my home phone left a message saying we are going to have to cancel your sons appointment as they had list the referral letter and couldn't contact my dentist at that time! No name no contact number left! I was appalled as no contact to mobile was made which I know they have as they rang me previously on my mobile when I queried the ref! My dentist confirmed no one had rang them which I never have experienced a problem getting hold of upto 530 pm! I promptly rang the dental hospital mon at 9 am to be told nothing can be done now and don't come at 930 as we've cancelled it and the next appointment is March 7 which is around 19 weeks 4months since the referral letter back on Nov 4th! Even more to my concern was the sheer disregard uncaring unapologetic attitude of the so called manager suite I feel my son has totally been let down here and I am very concerned the treatment being delayed could cause him to now lose the tooth as its been so long in getting an appointment and I feel staff losing notes and referrals is not a just reason to delay my child's visit even further ..appalling service or patient regard totally .