where is my parcel

We have been emailing courier guy about a parcel which they said have been delivered on the 29 of June. When we phoned them the lady said no its been returned cause nobody was at premises, which is a lie because I am here the whole day. We have bee sending emails which they only read and don't reply. You also have to hold on for more that 10 minutes just for someone to answer your call. We are still waiting from them...………………………..still no parcel:(