"No contact to date"

My son was referred for a paediatric assessment in relation to ASD by his speech therapist in late 2017. To date we have had no contact what so ever from paediatrics and no indication of a timescale as to when we might expect an appointment. I appreciate that this is an extremely busy service but surely some sort of acknowledgement that the referral has been received wouldn't be too difficult especially given the current waiting times for assessments?