Cant change FNB derbit order date

Impossible to change derbit order date, i have been calling fmb for the past 3 days now to cha ge my derbit order date and there isbno fork of assistance, they make you hold a call for 20+ minutes on these numbers *** and theres no answer, i am bery unhaopy with the service they give their customers. I jave been calling in the morning and afternoon and there is no assistance whatsoever, i have tried their live chat bu the agent said she cant help and i must keep calling these numbers but there is no luck!