Protecting myself and my account seems to be an impossible task

So my phone was ****** yesterday. I wanted to "remove" my banking app from my profile, for in case the ***** gains access to my phone's apps. The online banking does not give me the option to de-link my phone. Contacted FNB and had to complete a series of security questions, to which is apparently failed at one and could not continue with the process. Being a FNB Premier customer, the consultant told me he is going to put me through to Premier as they can "bypass" the security thing and assist me to de-link my banking app from my profile. Once I got through the guy told me I was transferred to him and I am supposed to call in directly, not be transferred. He gave me the number, dialed them again and got through to someone who now gave me another number again. Dialed that one and got to a guy telling me he cannot assist me, but he'll find out. I was put on hold. Few moments later the call came back with people talking in the background.. Then I got cut off. I just visited my branch and there are about 10 people in the waiting line. I only have 30 min lunch and cannot wait so long. How is it so difficult to help me with this? Yes I failed a security question, but the questions you ask are from like 10 years ago and I'm not even sure what question I failed. If I was a bad guy then WHY would I want to de-link the banking profile? WHY would I call FNB if I just stole someone's phone? Makes no sense. I just want to protect my account but no one can seem to press one button to de-link a app. I have no phone, so IF someone would have wanted to contact me to resolve this, please call me on my work phone *** - or email ***