Most Terrible Service Ever

Absolutely disgusted with the service! Paid for overnight my package was send on 31st of January on Tuesday, Thursday my tracking showed the parcel is in East Londen, Friday my package was still not here, late afternoon I contacted them to hear where my package is they said they will delivered it on Monday, Promised Monday! Now that I phone again to hear where the package is, they said it will only be tomorrow! So why did I paid more for overnight when it is a week already I am waiting and still not have my package!