Express Scripts Sending prescription without customer agreeing to price first Saint Luis MO

Happened to me already twice. First time doctor sent prescription to the pharmacy and Express scripts sent it out to me without me agreeing to purchase it. Prescription through work insurance company ended up to be $225. Its generic pill that have been in existence for years. Same prescription through Costco and Good RX - $53. At Cuban's Drug Cost company - its worth $16 to manufacture. Called them and asked them to match the price - they refused. Told them I dont want this medication from them - they insist they cannot do it. I didnt use those medications. Second time - Dr. again sends prescription and it gous authomatically to Express Scripts. I call them right after I get home (about two and half hours) - to cancel the prescription since its 5 times more expensive through them again than without insurance through Cuban's DrugCost or GoodRx. They tell me the system is down. I call again a bit later - they tell me the drug is already shipped. I told them they are pushing on consumers unwanted goods or service - because I cannot see it any other way. I am more than ready to return the medications as I didnt even open the second shipment and intend to drop it back at postal office and say I refuse this package. Its still not resolved.