Online payment not going through

I have been trying to Send money to another FNB Account but it's not going through. They sent me the otp number, i put it i and confirmed payment. At the end of my transaction when I check history payment, it does not appear and I am not getting an e-mail or sms to show that it was successful. I HAVE BEEN TRYING TO PHONE THEM SINCE 2:PM AND NO ANSWER. THEY HAVE BEEN PLAYING MUSIC AND SAYING THEY EXPERIENCING LARGE VOLUME OF CALLS. THEIR PHONE HAS BEEN BUSY SINCE 2PM UNTIL 7PM. THATS STRANGE. I AM STRANDED BECAUSE PEOPLE ARE WAITING FOR ME TO PAY.