Safair refuses tiny service dog to fly

We have a family wedding in Jhb and I booked our tickets from Cape Town to Jhb on Safair as their fares are the lowest. Immediately called their helpline to enquire about my husband 's little companion dog, a 2.7kg Chihauhau. My husband has Parkinsons Disease and severe Chronic Depression. This little dog is his antianxiety service dog and constant companion esp. as I work all day. I was told to email a letter/certificate stating this. I did that the very next day, a letter from.my Vet stating that she is well trained, well socialised and in good health. One week goes by, no reply. I phoned the help-line and was told the request had been escalated, I would receive their decision shortly. Another week went by. I phoned again, told it is still with Supervisor. I have 3 days in a row now. Today I insisted on a decision as i would need to make alternative arrangements, we fly next week. Eventually, I am told my request has been denied. No other explanantion. When pushed for an answer, the agent goes back to the 'supervisor' and then tells me I have not sent in the correct form, they need a certificate from S A Guide Dogs Association. I ask her where it says my husband, is blind, how can a 2.7kg dog be a guide dog, and has anyone actually read my request? I ask to speak to the Supervisor She tells me she is not available now and will get back to me. I tell her this is unacceptable and am assured she will call me by 4.00 this afternnon. Well, 4.00 has now come and gone. Is it unreasonable for them to allow this tiny dog, who plays such an important role in.my husband's life, to fly in a small box, that fits under the seat like hand luggage? I think they haven't even read my request, or supporting letter and do not really care enough to find out so they can make an informed decision. Does anyone have any suggestions? My husband really can't go without his little dog.