Absolute poor service by Voltano

I signed a application for supply of utilities(water and electricity) with Voltano on 27 May 2024. According to the application I was required to pay a deposit for water connection. No other fees were required. I paid the amount and sent the proof of payment together with the application form. On my utilities account for November 2025 (18 months later) a connection fee was added to my account. This is as I must guess the connection fee for my electricity 18 months ago. After emails requesting an explanation for this connection fee I am still guessing because Voltano does not reply. They only sent threatening mails and SMS massages to suspend my service.