Ground rent back dates

[Curdster]

I own a lease hold flat and was very surprised to find a bill for the ground rent for £200 and then a further subsequent bill for £500. When I question this I was advised that a rent review had taken place and the ground rent was now £100 per half year, up from £20. The £500 was that they had back dated the review but had forgotten to advise me as an owner.
I understand that a ground rent review was in the lease, but should I have to pay out for the inefficiencies of the freeholder not getting their act together at the review date? I am obviously trying to get out of paying the £500 but do I have a leg to stand on?

[mk1fan]

Post this in the Business Forum and you'll most likely get your answer. Failing that try Speed, Plod and the Law forum.

Alternatively give 'Lease' a tinkle.