A & A Corpus Christi Bail Bond

my son was arrested for assault a month ago. his bond was set at 3500$. when all was said and done I put up 5000$ and the title to a truck worth 5000$.. somehow that 5 in 3500 got changed to two zeros and came up with 30000$. we were all in shock. I knew it was wrong and I checked up and it was only supposed to be 3500$. the bond company scratched out 30000 and changed it to 3500$ which was what it was supposed to be. they now tell me they are pocketing 3000$ and threatning to keep all 5000$ if I try and argue with him so if im lucky I will get ONLY 2000$ back. I should only be paying 350$ out of pocket which is 10% of the bond and initially all I wanted to do was pay the full 3500$ to get all the money back so I wouldnt lose any money once my son went to court. whole point was to not have to lose any money. we are getting totally scammed. when I threatened to call a lawyer finally the guy who runs it got on the phone and threatened to keep the whole 5000$. he initially wanted 3000$ more for the bond. so in total they have 5000$ and a title to a truck worth 5000$ and was trying to talk me out of 3000$ more until I figured out THEY made the mistake. HOW CAN 3.5.0.0. BE ACCIDENTALLY CHANGED TO 3.0.0.0.0....? THIS COMPANY NEEDS TO BE SHUT DOWN!THEY GAVE ME [redacted],MY SON [redacted], AND THE GUY GOT OFF TO MAKING HIS FIANCE CRY AFTER TAKING HER TRUCK TITLE.