Non delivery on service agreement.

My parcel was logged as received last week Friday with a 4 business day delivery service. Yesterday was business day 4 and today all of a sudden my parcel disappeared off the tracking. Email at 8:30 ish to no reply received. Phoned around 11 ish to be told I now have a new tracking number and have to wait another 4 business days. Totally ridiculous, if they made an error you would expect them to change the delivery service to get it to the client asap - nope and they are so blase about it, not a care in the world about it.