Rated missed payment yet my account has been paid

I'm so not happy with cellc, my account is showing a missed payment on clear score yet all my monthly payments are upto date. I sent an email with proof of payment showing that I did pay the month that's showing as a missed payment asking them to correct the error instead I got an sms with a case number and no feedback. And they also sent me an sms to rate the service if I'm happy with how my case was solved yet they solved nothing. I got to call or response to my email