Refusal to answer emails regarding refund

On January the 6th our family traveled to Belgium from Johannesburg with Ethiopian Airlines, we had a stopover in Addis Adeba. When we checked in at the counter in JHB we were told that we could take our daugthers MaxiCosi pram with us onto the plane as hand luggage, therefore no tag was issued for it. When we boarded the plane it was taken from us to be stored, again no tag was issued. We had a transfer in Addis Adeba. When we arrived in Brussels (Zaventem) we realized that the pram was not transferred with the rest if our baggage. We immediately opened a case at the \Lost and Found"desk"