Bad service for delivery

I had a wonderful phone call with Kevin in retensions and upgraded my contracts. My issue is with the delivery company that you use. CourierIt has not contacted me directly and keeps saying that i am uncontactable. I called them yesterday and went to my work even though i was on leave and managed to get one device. Later during the day i got an sms to say my second delivery was unsuccessful as i was not contactable but i was not called or sms'd. The same thing happened today. I was advised by Kevin that they would inform me a day before the time, but in both instances i was informed the same day and never informed that they were there. Yesterday i used their option to change the delivery address, but their customer services lady told me that this option does not work and that they do not call or sms the recipient when they are there. How will i know to get my parcel if i am at work?