Billing Account, Incompetence to read

I emailed a claim of R750 to topmed with my new banking details to deposit the money to , called after few days to find out if all is in order and i was told yes. Last week Wed i reliesedthat they paid the money to an account that i neglected long time ago that is in arrears and am ****ed as i mention to which account they should deposit to and i called and i was told i should have called to change banking details and am asking how was i suppose to know that if i wasnt told. who ever that red my email should have informed me when they saw that am supplying the differenet account details. Chanel Schoonrad promised to call back within 24hours which she didnt. i aclled today i was told she is busy. my problem is the incompetence staff member who actioned half of the email i sent, as they neglected that informed them of the new banking details or advise me to call them if i want to change them and for that Topmed is liable in paying me that R750 as it your fault that you hire incompetence staff as for Chanel who failed to come back to me and inform the progress of the claim. i demand that money paid to my FNB acc that i nform topmed of ASAP.