bad collectors

my Woolworths account is handed over with them, i made arrangemets for payment but it seems like they are not paying for my account on some months. I asked for statement it took them two weeks to send and when i finally get the statement nothing corresponds. it looks like I've been paying them and they are not paying my account. i tried to contact Woolworths but they can not assist since its handed over. i hate the service I'm getting with this company.