"why can't I have choice to remove it now?"

I was having laparoscopy surgery for endometriosis and the doctor asked me just five minutes before my surgery about having Mirena coil, I told her that pills never suits me and this is also hormones so I am little scared of having it she said that this won't have much side effects as pills but said you might have some spots here and there ot tender breast nothing else. I was so nervous before my surgery so I said yes. But now after having it for 4 weeks I have never stopped bleeding, having lower back pain everyday which goes down to my toe and lower abdomen pain as well so went to family planning clinic for removing it and they said I should wait for 6 months to settle. why can't I have choice to remove it now?