got ripped off on trans rebuild

oneal transmission in clinton,indiana.took my 61 newport in for a rebuild,he told me $1200-when i picked it up it was $2500.00.he charged me $ 500.00 for a stock convertor,140 for a netural saf.switch.i was pissed,but could do nothing.i had nothing in writing,just verbal.never again without something in writing.sorry,just venting.
It seems every time i send something out to supposed experts I get shafted anymore , so I try to do as much as possible myself . It's a different world out there !