Unhappy with service given when phoning them

I bought voucher I tried to load it kept saying invalid when I call them they said it will be loaded manually within 24 hours when 24 hours finish and I call to do a follow up the keep telling me that they have escalated the matter to relevant department if not that they will say it will be loaded manually within 24 hour which means every time when I call I am renewing my 24 hours waiting time. I feel like in there, there is department or individuals who doesn't do their job