Unlock a Code on my DVD Player

Question

Good Morning!
I visited a Video Shop near my house yesterday afternoon and took a dvd out called Mr Brooks starring Kevin Costner.
When I got home I wanted to watch the movie but for some reason it was blocked. I phoned the video shop and they told me that it was a Zone 1 dvd. I had to get a number from them to unlock the code, but they couldn't find the number for the code that I had to provide them with - it's the code on my dvd player. I checked on google search and provided the code written on my dvd player but without any luck. Could you perhaps help me with the unlock code which I have to program into my remote control as per advised from the video shop?
My code on my dvd player is: LH-RH3690
Thanking you in anticipation
Kind regards
Deidré Fourie