Pathetic service from this company

I am very upset with the staff of RCS They phoned me for payment I explained to them I was retrenched and currently unemployed but will try to make payment as my mom will assist me which is a pensioner and she did I made a payment yesterday of R480 I used my I'd no as ref. Caso phoned me today telling me I could've gone into the wrong banking account and someone else might use the same ref. When I tried explaining that she needs to tell me where in SA do people have the same I'd no she told me I must keep quiet she is talking and I need to listen to her . So beginning of Sept 2021 I made a payment same way I did yesterday they managed to pick up that payment but not this one because according to her it went to the wrong bank account and I could pay someone else how the hell this is possible I dont know. So please explaine this to me who in SA has the same I'd no as mine and how could I pay someone else when the bank account no is listed with FNB.