Incorrect medication

I'm currently pregnant and don't think I should be taking warfarin. I've sent a script for my clexane and was assured that it will be send to me. Guess what! PMB and Medxpress knows what they did with my script. Instead of clexane they've sent me warfarin. Should anything happens to my pregnancy, I will surely hold accountable. I don't have any meds. Why send people wrong meds?