Payment Rejection Fee

I would really love to know how Telkom can justify charging me a R202.70 payment rejection fee when I battled to even get them to register a change in my banking details which occurred in June. Call centre takes you round in circles with that irritating automated voice with no option for changing banking details, calling into the store is no use as they will direct you to the call centre, no option to update banking details on the website or app and whilst I did send an email inquiry via the website which received a response, upon sending my new account confirmation letter through to them well ahead of my debit order date, no action was taken. So I must pay for sheer incompetence...