it was in April and my work permit is till November . The reason for refusing multiple entry was not explained but I read differences between aplications for single and multiple and I believe single entry is for employment inside Thailand when multiple can be obtained for “business trips to Thailand”
I paid 40k Baht for a full year lessons but if I ask them to generate the letter they will charge me additionally as they never did this letter yet. That's why I prefer to copy paste edit text , print it myself and give them to sign. The business registration will be easy to copy from them.