And Joseph is baptised as Pitt 26.5.1799 s of Joseph and Ann Pitt at St Mary Mag Canterbury
He had a brother Samuel Pitt -entry says privately baptised at Birmingham 24.4.1795 and publically in this church 26.5.1799
Could this be your Samuel Dinenage?
I think Ciderdrinker is on to something!
Although the army record for Samuel Dineage originally stated he was born in Canterbury, there is a notation below that stating he was born in Birmingham, and raised in Canterbury. I cannot make out the first two words, the second word possibly being "discharge". The notation is quite faded, so I have enhanced the contrast slightly.