disappearing airtime duplicated simcards

Would like to report that my airtime and data is dissappearing/Also i recieve deduction for services i didnt register with. From zimbabwe! So i suspect that my simcard has been duplicated! SMS I got: Y'ello! You've successfully renewed your CallerTunez Zimbabwe Kubatana at R0.50 for 7 days. Tone expires on 2018-01-19. Dial *136*44# to join MTN Music+ and U could WIN share of R600,000! 1 day FREE.