18 Months later the account is still not closed

In November 2015 I requested settlement amount to pay off the account. Credit Card account was paid off in the same month. However, today (24th August 2017) I learned my account is pending closure 18th months later, this is shocking service for such a big retail shop, when I asked the consultant why is the account not closed she just put the call on hold for more than 10 min.