Last week I have faced with read-only mode problem of my SDHC MicroSD card from camera.
You can read (copy) all data from your card, but impossible to delete any data from card or format it due to this bug.
There are a lot of articles about how to move physical Lock key in case of using SecureDigital cards (SD). But it is inapplicable in case of MicroSD :-)
I have tried to format my card using gparted but due to controller bug it was failed.
So there are several articles about Lock controllers in MicroSD cards and how to update firmware of it. But there are no guaranties that your card will working after updating process.
So, in my case I decided that better way is just try to exchange my card from seller on new (5 years of guarantee).
I have bought my card in Ulmart store (http://www.ulmart.ru) and they exchanged my card without any questions :-)