Is there any written note of promise or any clause that speaks of to work for two years or to serve notice period of two month?
You are advised to check the clause in appointment letter of the concerned staff. If the staff has alraedy submitted his resignation, immidiately sent a letter to serve the notice period or else your salary and all receivables are kept on hold for the non-copmliance. Do not issue any service letter or releving letter. You can send him a advocate notice for demand of training amount.
9th March 2018 From India, Mumbai
Was this promise verbal or as a part of his contract/job offer?
What was the nature of training imparted?
Can the amount be quantified as incurred for special training etc?
What was the notice period specified for exit in job offer/appointment order?
Before you draft an experience letter including these details ,first see what is the paper work and terms included i you offer which he has not complied with.
One must write only when he is sure about the legality of the words and circumstances.
Give clarifications to these queries for getting better suggestions.
9th March 2018 From India, Pune