Won't customer service agent

I have a cellphone contract with them my installment is R349 that was debited on the 31/12/2025. I got a message that I didn't pay and my line is suspended, the call center agent keeps on saying money backed but I submitted a statement that shows the money went through, the agents decided to drop the call. I don't know if I should take legal action because now my credit record is *****ed bad by then