Trying to give away items on shopify but limit to one per customer

[the_domj]

Dear Friend,

I am trying to give away items for free but want to limit them to one per customer identified with a unique discount code for a given quantity of items. 

I don't want to show pricing anywhere on the shop. So applying a discount code in its original fashion is not working.

Does anyone have any suggestions to accomplish this...

So the criteria are:

- Unique code to apply that we generate and are specific to each user

- No pricing anywhere on the site/shop

- We will still need contact and shipping information from the customer to fulfill

- 1 gift per code per customer

Thank you in advance for your suggestion!

Sincerely and Respectfully,

- Dom J.