Thanks for your informations, all these replies have been very usefull to me.
So far I havn't sign anything!
I worked for this company for years on freelance basis (I am consultant),and I always get paid the same rate.
I might be able to convince them to apply for a 3 months business visa. just wondering if it is really legal to work with it!
What I don't want is to work on a tourist visa, and be in an illegal situation!
I don't know what kind of problem I would face?

Otherwise, I will have to leave the country and make sur this company is blacklisted.

Thanks