"Phone calls not returned"

My son, now aged 15, has been vomiting sporadically after meals for the past 18 months and has eventually been referred for an endoscopy to try and find out what's wrong. He is otherwise fit and well and a keen footballer but is now increasingly becoming reluctant to take part in activities as that usually makes him feel unwell. He was referred for an endoscopy on 3 months ago and despite 3 calls to QE hospital, am unable to find out when potentially this may take place or indeed if he is going to be given one as calls either aren't returned after messages or a promised return phone call doesn't happen. I appreciate clinics and consultations are running behind and there is a lot of uncertainty because of Covid19 but a return phone call to advise what was happening would show respect and give me some confidence that my son has not been 'lost' in the system.