Builders cannot fulfill order

I ordered a water tank from Builders Warehouse on 27 September and was given a delivery date of 17 October at Polokwane. On this day, on hearing nothing from Builders, I started making telephone calls to the effect of eventually being told no stock was available and the order will not be met. If they did not accept an order for an item they were unable to deliver, I would have bought a tank elsewhere and would not have suffered inconvenience for another three weeks. The city where I live did not have municipal water for eight weeks and I needed this tank to store water delivered by tanker. Surely Builders should have informed me immediately when they discovered their incapability to deliver or better still not have accepted an order and payment if they were not sure they could deliver. I am sure they did not only become aware of this situation when I started enquiring om 17th October. I will never again order anything from them if it is not available on the shelve.