Dear Mr Nixon,
Further to my visit to the flat last week, I have left messages for your Landlady to come back to me regarding the cleaning to the walls which we discussed, however she has not yet come back to me.
I have written a letter to her and will await her response.
My response was...
Thanks for keeping me updated with the situation. Please let me know as soon as you've contacted the landlady, naturally as this situation has persisted for a month now I'm keen to see it resolved as soon as possible.
As a mark of good faith, I'll see to it that the money for this month's rent is transferred today.
To be continued...