Disgusting service -Samsung buy and get

I bought a fridge in november and got R6000 worth of vouchers over a 12 month period.my march voucher did not work.i have sent 13 emails and waiting 3 weeks and no one has sorted my issue out.i have asked for a managers email over 4 times and they just ignore my emails and send a flippen dum auto response email.this is such pathetic sick service from a brand like samsung.