REFUND DUE - STILL NOT PAID

I received a sms message from Absa stating that a refund is due to me for interest charged and that I should send my supporting documents. I contacted Absa in order to find out how legit the message is. They confirmed that there is a refund due to me, but could not give me an amount. They said that I should send the supporting documents and that it would be sorted out within 7 - 10 working days. I have sent the documents on 13 November 2017 already and I still have not received any response. When I contact Absa in order to query this, they say that the people that is working with this, has a back log. How convenient for the "people that is dealing with this" not having to feel the pressure, because they do not take phone calls. In the mean time, I have to sit patiently, untill they finish with their "backlog". Not knowing whats going on or how far they are with MY query. This is unacceptable.