Terrible customer service from Oh my cake Fourways

I experienced the most unprofessional and poor customer service from Oh my Cake Fourways. I place my order more than one month in advance for my sons first birthday. I ensured I paid upfront the full amount. I thereafter called the branch to ensure that they received my order and that they understood my request and design etc. The production manager assured me that she took additional notes and that everything was fine. Two days before my son's birthday I received a call from them saying that they unable to do a carrot cake for me and that I need to select something else. I expressed my unhappiness with this particularly because of the timing of them notifying me. I had several calls back and forth with a few people from the branch, one of the staff even promised me and said that they will offer me a voucher for the inconvenience and that I can expect the full refund and the voucher to be sent. Then at the end of it, they did not honour what was promised. I had to source a different baker to help me at the last minute with my son's cake. No apology or voucher was received from the bakery / management. I asked several times to speak to someone in management that could make a decision or hear my frustrations, but I am still waiting. I have never experienced such bad customer service from any company. The worst part of it all is that I placed my order in advance and paid in full. The least they could have done was to honour the request and do the order. They caused so much stress and anxiety days before the function.