DSTV acknowledge that a refund is due but won't pay it !!

Due to a stroke in 2019, my mother moved in to live with me. She ( despite great physical difficulties ) and I went to the Randburg DSTV to cancel her contract ( December ) For a further 5 months my mother's bank account was debited and DSTV acknowledge that she is due a refund of R4611. I have submitted a bank statement with proof of bank account details and payment ( as requested by DSTV ) but they are insisting that ABSA provide a proof of payment letter / document ! ?! ABSA do not issue such a document as they state that a bank statements are sufficient proof of payments. If DSTV acknowledge that my mother is due a refund of the above amount , why won't they pay her ! She is 88 and frail and I cannot get her to DSTV at this time, to do a face to face plea !