nonsense service

i Bought a R15 airtime and i could not see the voucher number at all, i then called MTN and they told me to take pictures of the voucher and send to them which i did, whoever i was told i have to buy new airtime there is nothing they can do. I have been in contact with a guy called Siphamandla Biyela and he did not assit at all no feedback what so ever. I have provided the serial number and all but still no assistance.