Hotpoint RFA52 Fast Freeze Switch?

New to site,please forgive any errors i make in posting this first thread.
Bought a new Hotpoint RFA52S fridge freezer And am desperately trying to find someone who can answer a technical question about the Fast Freeze button?
Whether i switch this ON or OFF ( 1 or 0) the compressor still cuts in and out according to the setting of the Dial Stat.
Previous different makes of freezer i have owned just override the stat and cause the compressor to run continuosly.
Is this not the case with this unit or am i missing something??
Is it just ,perhaps, that i have a faulty switch?
No help from Indesit/Hotpoint as they do not appear to have a technical support Dept.
to cope with such questions.
I would welcome any replies as soon as poss.