Contacting case manager

Hello everybody, Can anybody advise me how to get hold of my case manager as i need to know about if they are going to pay me back for a months money i have been paying back for 18 months as i found out that i do not actually owe them at all.  I was told i had been given 2 payments in the same month and it was not until clearing out some old paper bank statements that i picked it up and found i didn't owe it at all, i put all this in my journal and was told a case manager would contact me, that was 7 weeks ago, and heard nothing yet, so i left another message on there 4 days ago, and not even had an acknowledgment back, I am on LCWRA and as most of you know it barely covers your basics every month so with money deducted from that makes it even harder than it already is.                                                                                        So if any body out there has any suggestions, they would be much appreciated. Thanks.