Disappointment after disappointment with Zando.

On Friday, 20.11.2015, I received my order. The size was incorrect so I called in on Monday requesting an exchange. I was assured that the incorrect size will be collected from me no later than the next day and once received by the warehouse, the correct size will be dispatched. By Thursday, 26.11.2015, I've heard nothing from Zando and nothing was collected or delivered. I called the call center again to follow-up and again I was told that collection will take place no later than COB the next day (Friday, 27.11.2015). I specifically asked that the correct size please be reserved for me and sent to me as soon as the incorrect size is collected. Today (Thursday, 03.12.2015) 11 working days after requesting an exchange, I was told that the correct size is now out of stock. This was not my mistake. The correct size was never reserved/booked. And I am now sitting with no order. Yet I've paid. This is the worst service I've experienced! And also not the first time with Zando! They offered me no proper alternative or solution. Unacceptable!