Sending delivery details without available stock

Seriously disgusted with the service from Telkom! When I placed my order there was stock - I understand it can change at any time. BUT why send this message to me if there is no stock. I phoned in this morning as I was still not able to trace this waybill on courier it, just to be informed oh sorry there’s no stock and we can’t say when we’ll get stock. SO WHY THE SMS stating it’s on the way?!? Before I got this message I phoned to follow up and they couldn’t trace anything as my order wasn’t in the system yet - note this was 5 days after they did the credit check and advised they’ll send it soon. So sick of waiting and the CUSTOMER having to follow up!!!!!!!!!