Bad communication and lack of service

Ordered my parcel on 27 November 2018 and it still hasn't been delivered 6 days later. I have emailed, and called holding on for 15 minutes at a time just to be told there is a delay and they emailed everybody, which they have not. This is unacceptable. Communication is lacking and they don't really know what goes on, now it will be escalated because it will miss delivery for my mother's birthday.