I have voucher of rs 20 and dont get bal from that

Hi.,
My name is ajay gupta.
I am retailer customer and i sell uninor voucher to my customer. day after yesterday three customers they buy voucher of 20 rs complaint that they can’t get bal from that voucher those they are buying.
When i am try i get message like that, “Sorry this card cannot be used. Please contact our customer care service.” And then i am call at 198 (uninor complaint center). and i talled them that they just know me the voucher status but they are just transfering call to superviser or something like that. but even after 53 minutes hold i am not get any respond from him. then i just dis-connect call. and yeserday morning i tried to call again for same problem. but i am shocked that they are just ignoring me cause of i am asking the same quetion. they are simply say that ‘thanx to calling uninor’ or something like that and then just HANG UP the call. then how could i complaint for voucher those i get return today.
Please help me then i am happy to my customers. after all customers like a GOD for us.
I am sending you serial number of voucher those are scrached but dont get bal.
Serial No. : – 2110020105440131