SLOTASTIC - COUPON AND CD IN THE MAIL

So today after work I retrieve my mail from the postal box and I receive a letter and a CD from Slotastic giving me $50.00 free ND bonus.
I think hmmmm, I did play here on a free bonus maybe a couple of years ago and think well ok they want me to come back and play and deposit, nice.
I go through the download with the CD and before I start to play I go to chat and ask about the code and want to be sure I am eligible, I do not want any problems or I be said I was double dipping or using multiple coupons. (thanks to LCB for making this clear with all the good info here)
Anyway, the rep says he will look into and eventually comes back to say it has been used????
I ask what date that was as I know I have never rec'd anything from them before in the mail or email with an offer. He does not get back to me right away so I pop over to the cahier screen and alas it shows on todays date an attempted redemption and a decline of the code on the letter???
I find this very very strange as I had not even been to the cashier screen until this time and definitely had not attempted a coupon redemption.
In the end the reo states this is a personal coupon. I do not know what that means and ask him, no answer provided. I was just advised in capital letters there is nothing he can do.
I am very disappointed that one, I am sent mail and an offer that is redundant, 2- that a coupon was entered for redemption by someone, somehow but not by me during this process. I think this feels shady and am very interested to know if anyone has ever experienced such a thing?
Thanks,
Dory - chat pasted below;
Please wait for a site operator to respond.

You are now chatting with 'Anandi'

dory99: I was disconnected

Anandi: Welcome to our live chat service. My name is Anandi; how may I assist you today?

Anandi: Welcome back.

Anandi: I am sorry but this coupon is showing it is a personal coupon.

dory99: i do not know what that means. I received this in my postal mail box today with a cd to download the casino

dory99: addressed to me, ot anyone else, my address ec

dory99: not*

Anandi: I am sorry but there is not much I CAN DO.

dory99: Well I thank you and will ask that I be removed from the mailing list as it is very strange to see a coupon attempt made, declined when I did not visit the cashier

Anandi: You're welcome.

Anandi: Thanks for chatting and have a nice day. Enjoy playing in the casino!

dory99: not this casino I am afraid

Sorry but my first chat session with all of my questions was disconnected by an administrator as I was waiting so long for them to get back to me. So I do not have my series of questions that were not answered.

Hi.

I got the same cd and nd free code. I ask livechat why they send it to my because I had an account there for severel years so I knew I couldnt use the code. Weird.....must be a mistake.

You didnt redeem the coupon but livechat tried  I think.