Poor delivery service

The service is pathetic to say the least. They took receipt of my parcel on 27 November and I still have not received it. They do not update the tracking system. I have phoned on Monday, where I was told that the parcel will be delivered on Tuesday and when that did not happen, I phoned again, just to be told that the parcel is still being scanned in by the depot, but it will definitely be delivered on Wednesday. Today is Thursday, I still don't have my parcel, the phone lines are now apparently giving problems for the last 3 days, but I spoke to an agent two days ago. Emails are ignored and dm's on Facebook that you were told to send are also ignored. Poor customer service and poor delivery service should not be a result of faulty phone lines.