Do we understand emails and correspondence in English?

On about 4th April gave specific instructions - and confirmed by them in writing -pick up a Scan CD at Sunninghill Clinic - required by a Neurosurgeon in Benoni. After checking with them last week, I am told , we are waiting for your instructions to pick up - and today theu use a different courier Company - and deliver it to my house. Their charges of approx. R235 were paid when they were given their clear instructions. How much should I charge DHL for me to take the scan to the Benoni neurosurgeon? Just imagine if it was needed for an urgent operation!!