Data theft and poor dispute resolution - bring back call center agents

I bought 5G+5G LTE-A bundle at 21:00. I received a message at 21:16 saying I was left with 2555MB and by 21:00 I received a message saying that I was out of data - I literally was not streaming/downloading anything. I tried phoning the contact centre to raise issue but now there's no longer option to speak to an agent, they just refer you to whatsapp page which isn't helpful. This is not a way to treat customers.