Pestered for months to do an upgrade, and when I finally decide to do one, no one can help me!!!!!

I have been due for an upgrade for a year now, and have been constantly called by the Telkom sales team to do the upgrade. After a few months I asked to be taken off their call list as there were no deals that interested in. I recently came a across a deal on the Telkom website that I would like to take up - the deal is for an iPhone 11 64gb or 128gb. However, none of the stores I have been to have stock or are able to assist me. There is also no stock when I phone the online sales team. This has been going on for the past month. Very frustrating and ridiculous considering I was being harassed for all of those months to upgrade my contract but when I finally decide to do so, no one can help me.