I also purchased a very fragile nuc from Oswestry and was very disappointed with the "final product". Had my association apairy manager look the nuc over and his immediate comment was about the lack of brood and the relative low number of bees compared to a nuc the association had purchased at...
I would probably move it as the farmer in all likelihood will be determined to destroy your hive any way that he can. The destruction of the hive is the likely result of you standing your ground, irrespective of the rights and wrongs.
Once you have moved the hive (if you do) I would place an...