A Manager At Store #949 Voided An Approved Return.

 i had recently ran up more than 4 exchanges at a local best buy, but when i tried to do another exchange the manager denied it.  so i went to a different store to return my item and it generated a warning code reciept that said that further returns would be declined for 90 days, but it also said: that the present transaction was approved.then the manager voided the transaction based on the exchanges at the other store. he never mentioned this, but blamed it on a computer glitch. but i know that wasn't true because when i left the store,i called the 800 support number and a woman traced the reciept and said that it had just been voided. so in essence i had one last exchange allowed by the system, but the manager voided it. is there anything i can do about this as i feel that it was not fair as i never even shop at this other store. i swear i am not a problem customer but simply loss track of how many returns i had. is there anything i can do? as my purchase reciept is still within the 30 day period. here is a link to a copy of my approved return reciept:        http://i253.photobucket.com/albums/hh58/larzwarz/reciept.png