I'm surprised you are all blaming the Mirena when in fact the Mirena probably did not cause the infection as it is packaged in a sterile package. Infection is generally introduced into the cervical canal either through poor insertion technique ie not having a sterile environment or from (much less plausible) unhygenic practices. Its very disappointing for you to have to go through so much when it should be such a simple thing to have happen. All the best in getting back on track and I hope this serves as a valuable lesson to your doctors.