FNB - you ruining my business cause you wont change my contact number so I can get OTPs

I moved to Dubai in January 2021, but still run my company in SA remotely. I have been trying change my contact number on my business account with this bank for 5 months now but they cant do it because I dont have a SA number anymore. I cant load suppliers for payment on my business account which is having a really negative impact on my business. I have called the call centers, sat for days on hold being transferred from one department to the next. I have been through intense verification processes and being told that the number has been changed, which it hasn't. I have been in contact with my business consultant who says there is nothing she can do. I have been told the only way to change my number is in person. I really cant believe I am sitting in a situation were my company cant operate properly because FNB cant get there head around me having a International contact number. What do I do. Where do I go from here??? PLEASE HELP!