"Very poor follow up after surgery."

After surgery told my wife would need a scan, by surgeon to find extent of cancer spread. this did not happen. It is now 4 weeks since surgery and still no sign of scan. Told at last visit this would come through quickly, it has not. we leave messages but calls are not returned when we are at the hospital we are told all the right things but this is not followed up by action. Do I have to take this matter further. Could I have your reaction to this matter, face to face would be good. Thank you.