bad service on paid up letter

Its day two since logged a query with ackermans. No one has responded to me about the payment made to DMC Debt Management, to acknowledge that they indeed received a payment. I send an email to ********** with attached proof of payment. How is it possible for such a big organisation not being able to trace settlement payment that was made on the 18 December 2018 to current date. Yesterday i emailed proof of payment to your organisation as you requested. Even today no one bothered to call me about any progress on my query