So I have sent btc about a week ago. Because of major delays it got returned eventually. I sent the btc to my market account, this time with a higher fee and it went thru 
HOWEVER I log in today to see that the returned btc from the first transaction was sent AGAIN
AND this time to the same adress, but my market account has a changing btc adress and now I have btc heading to god knows whos wallet 
I never authorized the sending of the transaction the second time 
What is going on?
P.S I use blockchain wallet
Im so mad it would send my btc without MY authorization or even me knowing