Medical assessment advice.

My adult son is profoundly deaf without speech and can only communicate using BSL. We requested a BSL interpreter for his medical assessment which was at his home address. The MA arrived but the interpreter didn't. The MA rang her manager at CAPITA to inform them. We were told that another appointment would be sent by post. This morning a letter arrived with an appointment for the 14th of November! This was his original appointment day. I rang CAPITA who informed me that the original medical assessment had been recorded as a failed assessment and that l should call them back on Monday to get an update. Any advice on this would be gratefully accepted. Thank you in advance.