SOMEONE ELSE'S RCS ACCOUNT LOADED ONTO MY NAME

I am a RCS card holder. I had a look at my credit score and realized that there is an extra RCS account loaded onto my name that has a very poor payment history. I called RCS to raise this with them and was informed by Abu Kalam that certain customers were loaded with someone else's account and that I needed to send a screenshot of this extra account that is on my name to ***. I did this, no reply. I also emailed ***, email doesn't exist. My credit score has dropped because of this **** account being added onto my name and no one at RCS is able to help me!!! Also, how can they let this happen and not even inform their customers!!!??? Surely this is *******?? It is definitely *********!