Discontinuation of nandos vouchers.

I'm tired of being sent from pillar to post, I have been sent from one place to another. I have been given nandos vouchers that expire in March 2019 but when I go to nandos to redeem them I was told the voucher were discontinued if they were discontinued so what should happen to the old ones. Okay I call the call centre as advised. I call once more and the call centre tell me to go to the store and the manager is the ones that have to scan the voucher and they will send confirmation... Now again I have to again go to the store and explain the manager 1st declines an tells me once more that it's discontinued,but once I explain to her that I called the call centre then only she starts telling me that do I know how long it takes and encourages me to call the call centre they will give me a different wicode, okay I tell her no I won't go ahead has to do it... She takes it and then leaves for about 20min and comes back telling me that I should leave my details and the code will be sent to me, it's now 18:30 so once more I'm being sent away without a meal... Manager on duty - Sheron Call centre agent- Musa. My concern is why sell the vouchers when you know that you diacontinue them before they reach there expiry date...