After My experience Today, I would recommend that anyone planning to chip/remap there car do a baseline dyno run first.
One possible cause of my "problems" could be a failed/failing N75 boost control valve, If i had stuck to the plan and run a baseline before getting the remap done I would have found that problem and would know if it's the N75 or the Map.
In doing some reseach on the web it seems its possible for the N75 to fail in a number of way's
Open - Waste gate open = No boost
intermittent - Unable to control boost = surging
Closed - - waste gate closed = overboost boost
The plan at this stage is that the company who remapped are going to come back and check the N75 and if its faulty replace it. If its OK then we put the car back to standard !!!