Insulted by a call centre agent

I called a customer line yesterday (21/12/2015) morning trying to find out about my debit order the lady that assisted me said her name was Betty<br> while we were still busy on the phone I do not know whether she wasn't aware that I was still on hold she said to her Colleague she is dealing with a ****en stupid client here. I want to know is this how Cell C I training their employees to insult client whether they put them on mute or on hold. I am really not impressed, someone must really deal with this matter as soon as possible. Two and half hours later the team leader by the name of Dudu called me to apologise I did accept the apology from her but I demanded a written apology she promise to inform Betty's manager, up to now I haven't received anything so I do not know whether is this how they (Cell c)value their clients. I'm still angry because I don't know how are they going to handle this matter and what would be the verdict.<br> <br>