Im told I have a cheque account that i dnt knw off

I have been getting sms's from Standard bank telling me my acc has been handed over and I ignored because I don't have an acc with them have been banking with Nedbank since 2007 and the other day I answer the phone its Brooks and Lyt and Im told I have a cheque account with Standard bank yet when I first started working I opened a savings acc with then then closed it as I was now A nedbnk employee no calls where made to me no letters received and now I'm handed over for something I never even opened I call the Brooks and Lyt give them my ID number they are always off line and promise to get back to me and never do..pls advise what does one have to do in this case. I don't even know which branch this acc was opened at when as I need all that info as this is my name and credit record at stake.