Did you get a response?
It amazes me how many times this has happened to me - I have even tested it by giving low scores. Sure that this would then be followed up with some kind of contact - a phone call, an email....anything??
What is the point in implementing a process but doing nothing with it?
Those passives and detractors, the people who have given you the low-medium scores could still be turned into promoters.
Turn them into promoters and they will recommend, buy from you again and thereby increase your profits.
Ignore your detractors at your peril! Follow up, find out why they have scored you as low as they have - and DO something about it!