It is ridiculous and I would say that you are more than entitled to have a bad day with what you have been through! It is ridiculous that after fighting for your life you still have to fight to get what you are entitled to.
I had a similar experience earlier this year. I was diagnosed in March 09 and didn't work at my full time position throughout treatment. I ended up taking leave with out pay and working on a casual basis when I could. In February this year I tried to go part-time. I was still having treatment and had more surgery to go. I had a meltdown after a month and knew I couldn't do it. In desperation I contacted my super fund to find out what I could do. As it turned out I was told I had income protection but no-one had bothered to tell me. When I applied for it the insurance company gave me hell trying to say that I'd had a pre-exisiting condition etc etc. It was awful and it only made me feel worse. I too have been diagnosed with depression and am on Effexor and have been left with other health issues as a result of treatment. But it is always the depression that they latch on to. .As you say it's hard enough dealing with the consequences of what you have been through without having to fight bureaucracy! I would have given up but my partner helped me fight them. We even threatened to got to the media. My partner gave them 24 hours to sort it out or we were going to go public. We had a phone call within 24hrs. I won in the end!!!!
So don't give up!
Caren