Battery unavailability for Toyota hybrid cars

I am extremely disappointed with Toyota's support on hybrid cars. Within the first year, I had battery issues and Toyota Road Assistance replaced the battery due to dead cells on the battery the car came out with. Since April this year, the battery got weaker to the stage where it does not even last if you do not drive for 2 days. I took my car in on Wednesday, 13 Aug and was told that Toyota Road assistance put in a non-hybrid battery and that is causing the issue. I have to buy a new battery for R2500 and it will take about 3 days to get the battery from Toyota's factory in Durban. I just phoned to ask whether the battery has arrived to be told there is a backlog, it will only arrive on 1 September. How on earth can Toyota not have stock of a basic item like a battery? Then Toyota South Africa should warn their clients that there is a risk on buying a hybrid car as there won't be stock in South Africa! Or are the batteries just of such poor quality that it needs to be replaced regularly and hence Toyota South Africa ran out of stock? This is unacceptable.