Electricity Charges with no Communication or awareness. BLUADVANCE

I have been using Bluadvance for emergency top up on electricity for over 3 years. Recently moved out of my apartment and to my shock i OWE them over R1500. Sad part is current tenant is struggling to buy electricity with the meter number. I have sent over 60 messages on their whatsapp chat bot, (AI) no one bothers to call me or respond either than the AI response. They emails are also not responded. Called Blulabel call center manager Refilwe said she can't help me. I need to know what is happening and more over i need to get this sorted as it's not fair on the new tenant. BLUADVANCE PLEASE AKNOWLEDGE ME AND CALL ME OR RESPOND TO MY EMAILS