Disappointed with their service.

I'm honestly VERY disappointed in the customer care service. On 16 August I ordered a parcel and on 25th of August I went to collect my parcel only to receive half of my parcel. My parcel was divided in 2. I only received parcel 1 of 2 and parcel 2 of 2 seems to be missing. I called the call centre 5 times now and nobody gets back to me with the whereabouts of my other parcel. At this point I want a refund.