Incorrect Phone Supp**** after a month of waiting

I contacted the Call Centre wanting to upgrade to the iPhone 6S PLUS 64GB and having to answer endless security questions FINALLY got someone to upgrade my exisiting contract. When my phone finally arrived it was NOT the phone I ordered by a iPhone 6S 64GB phone. I once again called the Call Centre and the blame was placed with the warehouse who seemed to have made an error. HOW IS THAT POSSIBLE? Surely phones are not simply dispatched without someone QA the process? The incorrect phone is being collected today but when I call the Call Centre to inquire about the phone i ACTUALLY ordered I was told that the system has been down since yesterday and that no-one can assist. Surely they don't operate like a government department? The service is absolutely shocking and no-one takes accountability for their mistakes? If I ran my company like them I'd be out of business! Is it possible to actually have some-one resolve this issue without further frustration or do we simply accept that this poor service is the actual level that they are capable of?