Worst financial management ever

My mom was at N1 City hospital from Jan until Mar 2015. Since she could not manage her affairs from Jan until she died in Mar, I saved all the sms',s from the med aid for accounts that had been processed or rejected. All accounts that had been rejected by the med aid and which I was informed of, either by sms to her cellphone or by posted account from the service provider, I took care of and paid personally. NOW, on 9 SEP 2015!!!!!! when I thought all the medical affairs were long since over, I receive a FINAL DEMAND in the post for an huge amount, stating that my DEAD mom will be listed on ITC!!!! There has been no previous communication either from the med aid or from the hospital informing of any unpaid accounts and now they want to besmirch my mom's good name in death! The callous insensitivity and incompetence of it makes me devastated and furious! As I have sms's confirming the processing of large amounts by the med aid, I would like to know why there was no previous communications regarding this from Mar until Sep and I would like a full accounting of these unpaid amounts and the decency of sufficient time so that I can follow up with the med aid and deal with this