Breach of contract

I have exactly the same complaint as the person claiming FALSE Advertising. I concluded an approved Black Friday contract with Telkom Mobile on the Samsung A8 on Friday 23 Nov at 07:10. First debit order was processed 27 Nov. Telkom ********** phone me at 17:35 today and say they apologize and have no stock. The pre-Black Friday price was R349.00 per month reduced to R249.00 per month. They should at least offer a contract of normal value R349.00 pm but instead offer me the A6+ which is R299.00 pm and an inferior product to the A8. Will also report to the authorities if satisfactory replacement product is not offered.