OTP to access account

I've been trying to change a cellphone number for online banking with Standard Bank and their agents kept doing what I didn't request (activating confirmations for unknown debit orders and MyUpdates) and eventually after my fifth visit to the branch, I found an agent on Friday, 1 July 2022 who managed to activate the right cellphone number. The only issue is that I still couldn't receive OTPs on it, and when I enquired what I should do if it doesn't work AGAIN - he advised that I should call their Help Desk (which is not an option after waiting in the queue unattended for an hour and another time for 45mins).

WHAT I'VE DONE FROM MY SIDE TO GET ASSISTANCE: - Logged calls with various Standard Bank emails - only one that was promising came from Boitumelo Seete who mentioned that they've got backlogs, and linked a telephone call to their Help Desk that left me hanging for 45mins with no one to assist. - I visited the branch near my house 5 times with no resolution to what I need to access my accounts online - Made several calls where I waited for close to an hour without assistance, until my airtime ran out - Tried resetting my password online only to get an error message that my account is not set-up for OTPs, SMS or emails and after several attempts that my credentials were not registered and the account is blocked (which is strange because I've been using Internet banking and Standard Bank App from a different phone for years). All I need is to do the same from a new cellphone number. - Tried accessing my accounts from the Standard Bank App and my credentials are not recognised. - I can transact at retail stores and managed to pay existing beneficiaries from an ATM (it was the first time, because I was trying all avenues I could not to stay behind on my account payments even though it's not convenient and risky - but this is limiting because I can't load or pay new beneficiaries from this option)

Standard Bank created this App and should have the flexibility to attend to customer changes and requests. Not being able to change a cellphone to receive OTPs for online banking is frustrating, and I've been working on getting a solution and assistance for two months now. At this point I'm wondering if I need to close my account - will that be possible?

I'm tired of visiting their branch, making calls, sending emails and trying to override the error message online to access my accounts. I need Standard Bank to assist with resolving this.