SIM card catch 22 situation

I have been trying to get a new SIM card from FNB for the last week. This is proving to be a real challenge. I first tried using my online banking. the system either refuses to accept my cell phone number, as you have created two separate boxes for a cell phone number.I tired all the options or it simply gives a ERROR and a Ref number, with a contact number. I was told to then go to the SEA Point branch to get a sim card. Well after 15 minutes of FNB trying to find out if the actually had any Nano sims cards I was told they do not, and I must apply online. One would think getting a FNB sim card is a simple task, especially as Im right next to FNB bank. Please can someone from FNB please get me a prepaid Sim card for my phone . ***