Very poor service

My mom accidently paid her rent into Multi choice account on the 2/3. They have been in contact since then sending banking statements, id's. It is still not refunded even though my mom have told them that it was her rent. She only receive SASSA pension and has been a client for many years and they just do not care. During this time she has literally spent hundreds of rands in airtime to try to sort out this problem but still no success. Her health is also very bad and she has been in hospital numerous times and this situation is just worsening her health with all the stress.