bad service

I went to jet store in Feb last your to ask how much I owe, they gave me my balance on my account I then paid the balance and asked to close the account as I did not want it anymore. they called the call center and closed my account. to my surprise a few months down the line I start getting calls that my account is in arrears. I then explain to them what happened and I was promised to be called back they that tye would sort it out. but no one came back to me. I got about ten calls everything they tell me the same thing that my account is in arrears, and I keep telling then the same thing that I do not have an account I canceled they all promise to investigate but no one comes back to me. now my so called account has been handed over to their debt collectors MBD, I must now agree to pay money for you incompetence. you guys are just bad service a ******* a company too quick to open accounts but when one wants to close the account you are slow and don't do your jobs properly, I went to jet store on Monday the 17/08/2015 but no one could help me just people with bad attitudes with no customer service at all. the call center say the last payment was a debit order of R37 in 12/2013.