Pitton Plumbing & Heating Inc

We had called Pitton because there was some plumbing work that needed to be done and they were first - late hours and weren't able to get a hold ofWhen they came, they worked for 1/hour but told us the minimum billing time was hours which we were fine with- he said the cost was $and they needed our credit card info before when we had hired them in order to be able to send out the guy
We get no invoice, no nothing andon our credit card bill- it shows a charge from Pitton for $864!!!! that's more than double of what they said
After making multiple phone calls and getting no results- nothing has been resolved and I just want to know why I got charged that much!