Contract signed but no stock provided

On 11 February I signed two cellular contracts with Telkom Mobile. At the time no stock of the phone advertised (iPhone 5S) was available, but the sales assistant assured me that within a week stock would be available. I requested that the phones be made available at the Somerset West Branch. He indicated that this would be possible. After a week (18 February) the wrong phones arrived at the Pretoria branch. The assistant assured me that the correct phones had now been ordered and would be available in Somerset West. Then he went on leave. When he returned he claimed that he had the phones and would organise a courier to deliver them. On 27 February I provided the address. He claimed he was organising a courier and the phones would arrive within a few days. Then he went on sick leave. When he returned he claimed there was a problem with the courier but he was working on it. It is now a full 5 weeks since signing the contracts the assistant does not return my calls, has colleagues make excuses when he is not at his desk, and no sign of any phones.