Blocking access to your own account after permission granted to transact while overseas due to a new policy being instated AFTER permission was granted!!!

I was going to be travelling overseas and went in to the bank to ensure that everything was enabled and all permission given to enable me to transact via mobile and internet banking and that the OTP would be sent via e-mail as I wasn't sure if I would have access to my mobile number. I was ASSURED that everything was in order and that there would be no problem. The first time I wanted to access the funds in my account I was blocked as they would not e-mail the one time pin. When I queried this they told me that their policy had changed & it would not be done. It was changed AFTER I left the country and was still away and I was supposed to now "come into the branch" to sort this out!!! How can I possibly do this when I am away? Surely if a policy changed it would come in to effect from that date forward and not have any effect on what is already in place!!! I now have NO access to my OWN money & cannot even transfer money or pay beneficiaries! This is NOT acceptable! Each time they are contacted they will come back to you in 48 - 72 hours and no solving of the issue! I want access to my money and account & they have no right to with hold it. Do NOT recommend FNB they do not go by proper banking instructions