"Terrible medical experience"

I went in with a bad cold and told the nurse and the doctor both that I was allergic to penicillin. I was given a prescription for cefalexin (which has penicillin in it). When I expressed my concern to the doctor, she said it would be fine and just to take it anyway. I repeated my concern and she refused to give me any other non-penicillin antibiotic. She said to call back if I had any sort of reaction and they would give me something different. When I went to get the prescription filled at the pharmacy, the pharmacist was shocked she would give me a penicillin when it said right on my medical information sheet that I was allergic to it. Unsurprisingly, not even a day after i started taking it, I had an allergic reaction. I called back and was advised by the nurse to go see a different doctor somewhere else. This has been the worst medical experience and the biggest inconvenience ever. I will never go there again.