How can I fix my Nissan cd stereo?

I recently had a Parrot bluetooth car kit installed and the person who fitted it tried to turn off the code on my Nissan radio. Unfortunately this seemed to activate the code requirement. I went to Nissan with the full details from the radio but everytime I input the code I get 'Wait 1 H' and it eventually goes back to 0000. Nissan seem to think I am just putting it in wrong and claim I now need to remove my radio again to check the details.

I cannot remove my radio myself (and I am no longer with the person who did it) as it is set into the dashboard and Nissan will charge me £40 to do this.

The code I was given was 9852 for Nissan MM CD-K:
BP 234 632 s11240

Nissan then told me if I try too many times it will secure itself and it will cost me even more to sort - any ideas or help please?

My Micra is an 03 plate and I have other details from the radio as all numbers were taken off when it was originally removed.