Prblm of Lower category profession to Higher category visa stamping

Hi sir,

i was in saudi arabia for two years and mine profession in visa was Labor category even though i was qualified for high category. Company did not change even though i requested to change. After  finishing company contract I came India by Final exit. Now i have got a new job in another company and they have issued visa. but this visa profession category is high. Travel agencies told me that embassy does not stamp visa from low to higher category. But, some travel agencies told me that they can do it by using their "hold" in embassy (through setting) if I pay some amount of money.
   So, can anyone tell me that is it a risky way ? Will I face any problem in future if i get stamped this visa through this way.. ? (In airport or while taking or renewing Iqama) . I get doubt because, that old visa page in my passport will remain same only..
     Or is there any alternative method ?.. Taking new passport or something else .. ??