Appologise for posting twice, not sure how to delete other thread.. Yes the deposit is third party

My Letting Agent has just rang to inform me that the house my family has just moved out of was 'not upto scratch'. He wants a invoice of the cleaners who done the carpets as it 'stinks of dog still' and wants us to repaint kitchin and our sons wall as 'its uneven'....... I obviously took this personaly as I am a self confessed clean freak and that house has NEVER stunk of dog! Yes the painting may be a little uneven, but not noticeable unless you staired at it! I retaliated in reeling off a list of probems we've had with the house since we moved in. I was then told I was being 'pedantic'! The problems we have had is amazing and we have had to sort out the chasing companies, arguing and planning in works, not the letting agent or landlord! We moved into a 3bed house with garden, car port, en-suite and the usual. The ensuite shower didn't drain away properly (leaked into lounge), car port- too steep drop, so our car bottomed out (my other half is in the trade so when they tried to palm him off he quite rightly laughed in their face) and ohh my the garden! First half was like the Sahara and the 2nd you could grow rice in, it was that bogged! So as you can tell we did not renew our tenency agreement and they want to take money off us for 'dog smell' and a bit of paint! Can anyone advise me on how I would word a strong letter telling them to 'get stuffed' ?