Failure to deliver Electricity Token on numerous occassions

Our school uses FNB and I am the signatory. Each time I buy electricity in our banking profile on the laptop the SMS with a token does not come through. I then have to spend a lot of airtime talking to agents of the bank who are of no help and busy telling me that they will escalate the matter to the back office but nothing happens. Today at 10H00 I bought electricity for R1500 and the SMS did not come through. I reported the matter and received a reference. Around 14H25 a guy called me and told me the reason why I did not get the SMS is because I blocked certain numbers with my spam call detector. He advised me to unblock all the numbers and restart my phone which I did. But then again no SMS. I called the bank to report the same matter again. The lady who assisted me insisted that I give her the reference number which I did not have on me but was provided by her bank. She couldn't find the reference and now had to log another fault and create a new reference number. My issue is, why is it possible to buy electricity on the FNB website, but impossible to resend the token should it not arrive, or even view it on the website for that matter. FNB is making it harder to do business because they are far behind with technology which is not in keeping with their slogan of "bank of the changeables". More like bank of the stone ages.