Incorrect "non-payment" notices despite proof of payment and confirmation from consultant

I have a payment arrangement with Landau, agreed at paying the set amount by the 1st of every month. I made my payment on 27 August 2026 — ahead of the deadline.

On Friday, 4 September 2026, I received a call from a Landau consultant claiming my payment had not been made. I explained that I had paid on 27 August 2026 and sent proof of payment via WhatsApp to +***1, using my correct reference number. The consultant then confirmed she could see the payment reflecting on her side.

Despite this, on Monday, 7 September 2026, I received an SMS from Landau again stating that my payment had not been received and instructing me to pay immediately to avoid further costs.

This is unacceptable. I have proof of payment, I used the correct reference number, and a consultant already confirmed the payment was received — yet I am still being sent threatening notices about non-payment. This is causing unnecessary stress to a client who is honouring their payment arrangement in full.

I need Landau to urgently correct this on their system, confirm in writing that my account is up to date, and explain why this error occurred despite the payment already being verified internally. I expect this to be resolved without any further threats of "additional costs" being added to my account.