Boost m review: They won't cancel account and turned me over to collections

I only kept them two or three months because their service was bad and they lied to me about seemlessly switching between three carriers. I canceled the last 3 or 4 days of my service and ported my number. Got an email saying they were going to take out my next payment in a few days. I changed my bank account number and they tried but failed. They kept trying for about a half a year and now they have turned me over to collections and I don't know why because I don't own them anything, yet they want to put a blotch on my credit score. I guess they must think they are the hotel california where you can check out anytime you like but you can never leave.