I have some insight here. In previous years you were able to transfer within the country, but the Labour office now insists you get a new non-b. Technically immigration can do it, but then you will struggle for the work permit. Best to start afresh....
In my experience I have yet to be asked to have my degree verified. It could prove problematic as I am South African but graduated uni in the UK. Near as I can tell, I've been at my job a number of years now and they only ask me what was required at the time. If I changed jobs it could be problematic but so far so good!
I have been a member of this group for some time now. It seems that the immigration system is full of rules designed to keep foreigners out. I personally have not had any issues with immigration. That said, I am a 37 year old white male. Every year I have to prove myself more and more. I am a licensed teacher at an international school. I hold a degree in linguistics and upon visa renewal I had to take a test proving my English proficiency. I am South African thus considered an undesirable...