Poor communication and service

On 15/04/2020 I received an SMS from WesBank alerting me to the fact that I finance account I have with them has been closed and there a refund due. I also received a detailed statement by email that indicated that the account was closed in January and that account was overpaid. In the SMS WesBank said that I needed to prove my ID and bank account which duly did. I then receive a mail with a reference number confirming that the refund has been requested and that I should allow 3-5 working days for the refund to be effected. Later in the same week I received a mail from WesBank wanting me proof of payment. I sent WeBank proof of payment for at least the last 6 months. Since then I have not received the refund due. I have been writing to WesBank asking what proof of payment do they want. I get no response to such inquiries.