Cannot resolve a simple Error 217 via email

I am based in the UK. My FNB account has funds which I manage from here. My account has regular direct debits. I tried to add a recipient on my online banking only to get an error message 217 unable to debit this account. After emailing FNB with the above information as well as my UK number, I received an email stating that they could not get hold of me and that I need to visit a branch. Forgive my language but this is absolute ****! What is the point of online banking if I get told I need to visit a branch, and what am I meant to do when I live in the UK?? Should I just not have an FNB account and switch to some other bank that accepts me managing my funds from abroad? I am only due back in SA next year so I am not visiting a branch until then.