Thanks for your reply.
The letter has been sent to the company owner about a month ago
I already spoke to my Supervisor about my salary and she agrees that I should earn a lot more money for the duties I do.
But it;s not down to her nor to the "Office Manager" - it's down to the Company owner...
I jhave been offered a new IT Job with a different company for 4k more than I'm on at the moment.
So I'm in a good bargaining position.