The chance of getting any one hand in particular is 216:1 (I believe). Going off this information, getting a certain 4 pocket pairs in a row, is (261:1)^4 which is 4640470641:1 (my math could be totally off, but whatever.
). Each of those times, when facing a smaller pocket pair, you are about a 82% favorite (from card players hand calculator). So not every single time you will win.
Everyone has those bad run of cards. I'm sure you are just exaggerating, but if you aren't then it's just bad luck. No one can control the cards every single time, so people will hit there one outers once in a while.