Can a bank withdrawl a customers credit card account and hold it until i find another form of payment?

I had recently got involved with a company called apex mercant group so my small buisness could receive credit cards. The sales rep. told me nothing but lies paul price.... He promised low percentages of 1.73 % per transaction, and just $9.95 monthly.... Wrong I used it about five swipes realized that was not the case.. Called him back he said he fixed it but he didnt they still are doing no diffrent. Tried to call paul price back no answer and no return calls..So this last transaction swiped for two thousand which is our limit on our papper work through apex , i find out that later this transaction is being held cause we went over our limit of one thousand,(middle man fifth third bank)... but i have already had a transaction of 1500 dollars? just a few weeks prior, we send in bank summarys , invoices and the ladies card statement showing the withdrawl out of her account.. they told me to find another form of payment but why and how can they hold the money in there account if they said we cant even swipe for that amount in the first place.. why did are machine say approved, gave us a reference # that authorized the transaction.. our paper work from apex stated maxium of 2,000 as we used in this case... It all seems to be a scam.. what are my rights what can i do .. the car that was worked on was already released..