I certainly can believe it. Had a client did that to us once and we have lost 500 (from cost of server, lost revenue and chargeback fees) just from one client who charged back for no reason. Banks certainly need to be more vigilant on errant clients who's using chargebacks to get out of paying for anything.
I hope you got it documented well. We did, but of course, Paysystems is just hopeless in helping us. I didn't even get a reply on the status and it has been months.