invalid voucher

On the 12 Sep 15 we purchased a landline recharge voucher frm pnp, we ddnt punch it in immediately as there ws still airtime on the phone. On the 24 Sep 15 we tried to punch in the voucher it says voucher invalid,i contacted the call center the very same day . I spoke to Thabo whom i gave all necessary info as he requested and he promised to escalate the matter to the technical dept they frm their side capture the voucher pin and i will receive a call later that day up until nw i hvnt heard frm them. Fair enough,i contacted telkom again today spoke to Delian then she transferred me to Asanda who told me tht the voucher shows frm her side tht it has xpired even though xpiri dat is 2018 then Moipone who ddnt hv a clue of what i was talking abt. I find it difficult to understand tht a prepaid land line voucher bought frm one of the reputable supermarket cn gv ppl such grief. I need to knw wat r we suppose to do with the voucher(100)since we r told that it has expired n why were we told tht it b captured or recharged frm the technical dept. We r very disappointed at the service received frm telkom.