Over Billing

I have had the worst experience with this company over charging me.  I had major trouble from the start.  Billed for 4 phones at $289 a piece. I paid for the phone when I ordered their service.  They cancelled my order because "I didn't pay". Took forever to almost fix that.  I also had two sprint wireless pc cards.  One of my laptops broke so I out 1 card on vacation mode to avoid the $200 early termination fee.  The guy in India, who didn't speak English very well, then put both cards and my phone on vacation mode. They next thing I know, I'm being billed up to $800 bucks a month.  Who do you know would actually call a creditor up and say, hey I am tired of paying $50 a month for your service, let's make it $800 or more a month.  They ran my bill up to $2045 and I didn't even have the service anymore cause they cut me off.  They wouldn't even talk to me anymore.  What can be done about this kind of practice?