Nedbank Bad Service

I have been trying to cancel 2 debit orders on my chq account. I went into the branch & was told to do it on line however it's impossible. Then Nedbank mailed me to say I must call Sage direct. This I have done countless times plus e-mailed with absolutely no response from Tamsin van Rooyen who is apparently the ONLY person that can assist me. I am just passed from pillar to post with NO JOY.