I have 2 decks I use in Diamond and when I play the Mage ALL I PLAY AGAINST are Mages. 10 out of 13 games have been against Mages.
Yet as soon as I go to my DK I face nothing but DK’s and Warriors NOBODY else.
When I go back to my Mage AGAIN only Mages.
Confirmation bias, because selfishness plays tricks on us. 10 games is not a sample; it’s pure randomness; record at least 60 to 80 games and check again.
Yes, it has already been proven many times the game is rigged. The real question is what are you going to do about it? Hopefully not waste your money…
Yes, the game can make your progress blocked when ever it wants… if you can’t win enough, it won’t let you rank up no matter what kind of deck you use… I am using a not meta deck, self made and if the MM can’t make me lose against meta decks I get Rogues and Priests only… Why? Because these classes are using random and copied things… RNG can make me fail against these easy. 
Try to figure out why you can’t defeat your hardest opponents and modify your deck to get a chance against them. The game was terrible for me yesterday too… 2/8 win only… could hardly make win 2 games quest completed. These are not bothering me anymore… until I can win enough to rank up and more often reach Legend… I am alright… because I feel my success for my own with my decks. The game let you rank up only if you are good enough. Learn from your mistakes and then the rank up will arrive too.
How exactly do you suppose they would sell their junk if they didn’t rig their game to bring you to the verge of insanity and buy the strongest meta cards out there ?