Does anyone know how long it takes for the loyalty credits to become available , I have some after buying the Mavic and would like to put them towards buy some Accessories

Mine became available roughly 2-3 weeks after the Mavic was delivered. Have just used it to order another battery, the filters and set of props

I ordered my Mavic on Nov1st and didnt receive it until Dec 20th, and then received the credits on Jan 13th.. so anywhere from 2 to 3 weeks maybe 4?

3 to 4 weeks on average

Does anyone know how long it lasts before it expires?

I received my Mavic Nov. 10, and then some accessories a few weeks later.  I finally had to send an email to DJI to get my credits applied.  After a couple more weeks, they were just applied on Feb. 14.  Sometimes .... they forget.