Goods paid for and collected but not received

I had placed an order to collect a small parcel for me for same day collection & delivery. I was informed yesterday by the person they needed to collect it from, that the parcel was collected just around 1pm. I have had no contact from The Courier Company with regards to when I will be receiving my parcel and cannot get hold of them at all. They also do not respond to emails. I am in desperate need of the package as it is medicine for myself. I have already spent the money on the medicine and cannot really afford to pay this person again, let alone another courier company. I am highly disappointed in the service of this company and find it totally disgusting that you cannot get hold of anyone.