I haven't. There are popular boys I like, but in my experience there is an inverse relationship between price/fame/attitude and performance. Everyone can call themself a model (e.g. advert by V-club massage: our masseurs are actors, models, TV stars... all bullshit, just some boys they grabbed on the street).

It might be that they are inundated with messages and haven't even read your message, or someone else managers the account and thinks your request is inappropriate, or they are just not interested. Did you message in Thai or in English? If in English, they might not understand and just ignore.