Disgusting customer service from FNB call centre Agents!!!

I simply wanted to use my Ebucks account which was set up 10 years ago. I now have a new number and needed to access this account and in order to do that I had to change my Incontact number with FNB first. The one afternoon I called in the agent gladly changed it, so I thought. She then put me through to Ebucks and the agent there tells me sorry itts still not updated and I should call FNB again do do it again. Tried to call but no answer from there call centre even though their trading hour ends at 6pm. I then tried the secure chat and asked that it be changed, the agent sent me a step-by-step process on how to change it via the website. Bearing in mind I have tried this before and the website pushed out an error saying the functionality is disabled. Anyway I tried again and still the error popped up. I explained this on the secure chat and now the agent changed and new agent says sorry they can't help with such requests. This is all happening at 5pm. He then says I need to go to a branch. Sarcastically I asked which branches are open now and he checked the area I was in and said sorry they close at 5pm. No joy there. The next morning I called 7 times, and each time I spoke to a different agent asking for the same thing, I got a different response. The first one was incredibly rude, she didn't ask for my name or ID, only that I have to go to a branch to change my Incontact number. I said to her that the lady the day before had done it and didn't tell me that. She said she can't vouch for what other agents do. So I asked her "is that it?" and she put the phone down on me. The next call I made, the agent said sure she can change it but I need to answer questions to be verified. I said ok and she proceeded. The questions that were asked aren't answers that I have. She asked me to go to my app and give her my last card transaction amount which I did but apparently was wrong. I failed this verification and she told me to call back and answer new questions. By my 7th call I had already wasted a R100 worth of airtime. I complained on Twitter and a complaint was logged, that was two days ago and I'm still waiting for a response. Why is that the agents are not consistent and uninformative? Why are they so incredibly rude as if we are bothering them? Why is the process so ****ty to change a simple phone number? Why don't your agents know your products? If secure chat can only address certain issues, why do you not have toll free numbers for people to call on?