Bad service, lies told to me

I am so disappointed in my bank. Well fnb connect you advertise an Xbox 1s for R299 x 24months. I called in to accept the offer they tell me everything is done. Then the next day they say something is wrong they have another deal for R329 x 24 months two games I accept that the next day and then I get told there's a problem with the system they can't choose it. How does it go from everything is successful you will get an sms to confirm your delivery to there's a problem with the system. That happened on the 30/11/2020 I got a call on the 01/12/2020 & 2/12/2020 for a new sale and told them what's going on. I was told a manager will email me nothing happened. Was advised I will get a call to notify me if they have stock on the 04/12/2020 but they cant promise I will get stock the weekend as I explained it's a present. I'm disappointed in the system and the false advertising as they could not keep they promises I have all the screenshots of the advertising. It is supposed to be a present for my child. Really disappointed and even considering moving banks if this is the service I'm getting.