Courier guy overnight delivery is non-existent!

I paid R150 for an overnight delivery. Their website claims that overnight deliveries take 1-2 days. My parcel was sent through on Tuesday, meaning it was supposed to get to me by Thursday latest. Friday was beginning of a long weekend. So I have to wait till Tuesday to receive my parcel. Basically, I paid for a service I didn't receive! I paid for an overnight delivery to avoid having to wait throughout the long weekend but even with that, I have to wait! This delivery can not be classified as overnight so can I get some change back?