Angry and disappointed

Cellc does not want to admit that they messed up..now they wanna send me sms to contact attorneys for payment arrangements..today I received an sms where they offer 30% off on my total. Omw why would they do that..they know they sent courier to fetch device from me..now they don't have records of it. They don't do their work properly and they should listen to their recordings..I am not a *****..all my accounts up to date but cellc affecting my credit score