Pathetic customer service from Cellc

CellC is the most pathetic service provider! My sister had three contracts with CellC. They terminated two contracts without any communication with her. Even though her account was up to date. Cell C now wants her to pay the remainder of the contracts without restoring the line and continually disconnect her up to date line. We want to sort the issue and there is simply no communication from their side. She has been their loyal customer since 2011.