Obstructed catheter

I am new in the forum (although I have been with the insulin bomb).And I have been 4 catheter for a month, 3 are encoded.It had never happened to me.I have changed the insertion areas, I have used ancient catheter ... but it's nothing like that.They are always encoded and make me injured, because sometimes they even fold out x out of the skin and only the elbow enters ... Nobody has had problems with the prick/ inserter?It's the only thing to change.It cannot be that for 2 years everything has done well and now not.As "veteran" says, I want to throw the bomb ...

My son (he is an adult) at the beginning of carrying the bomb, they were all a horrible one, it was horrible because between we were rookies and we had a fatal problem.The solution consisted of changing the 9mm and putting the 6 mm.(That children use) It seems that the 9 mm is very thin.When playing the muscle they folded.Since using 6 mm.We didn't have that problem.