cancelled debit order and requested to do eft

When I got retrenched in May 2022 I informed Tshipinoto funeral home. I requested to do eft as soon as i get my uif monthly, and they even sent me a form, which i filled and returned as per instruction. Only to find a bank notification of R7 for insufficient fund , as they tried to debit on the 25 Nov 2022. On whose authority? what happened to the agreement i had with them. And every single month after doing an eft i send them proof of payment. After i saw what transpired over the weekend, i sent asked what is happening on their whatsapp number, no one bothered to respond nor call me. They can call me on ***