They suspend my home line and stole my airtime

Our line landline is suspended we bought airtime and call the billing department unsealed the line Nozipho Khuzwayo who was assisting on the day ask for the voucher number of the airtime and she said she will load it, later when I call again as the phone was not working only to find out the airtime was used by who I don't know even Telekom don't t know what happens to that airtime, I'm calling g Telekom everyday and they escalating the matter everyday I don't know what to do now as I need the phone working