Basing on the first paragraph which is applicable only for Working/RP Visa, what if after 2 years(employment ban duration) still your previous employer will not issue NOC,what is the remedy for it?

In addition pls, this maybe a special case, what if your previous employer issued you a Business/Visit Working Visa? Do NOC is required when you resign? or Do the 2 years(employment ban duration) is applicable, when you go out qatar?

thank you again.