Afrihost complaint

On 30 December 2020 I spoke to a consultant at Afrihost as I made a error regarding plan upgrade I cannot remember his name but he said that he will downgrade it back to what it was and that I wouldn't be charged. Today Afrihost charged me R529 instead of R399 and says this is due to the change being done during billing period and that the charge is done by Vumatel and that Afrihost cannot do anything about it even though the Afrihost agent confirmed that I will not be charged at R529 . Why am I being penalised for the agents mistake. This is blatantly passing the buck and I have to bear the brunt.