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.

You should check your State laws on that because in some states not having a signed work order is grounds for refusal of payment and you still take your car.
I did exactly this for a living (in a trans shop) as the service writer in two different states, so I know the laws are different.

Examples:
In Cal. there MUST be a written estimate of work and cost, and it cannot be charged over that estimate unless at the very least you get a phone call asking for more money and the reasons why.
This phone call MUST be noted by person talked to, amount the work order has changed, why the order has changed, who was spoken to by the shop person along with the time and date written as an amended cost on the work order.
If this procedure is not followed, the owner of the vehicle is not required to pay any more than the original work order estimate.
If everything is followed correctly by the shop and the owner of the vehicle does not pay the bill, the shop can keep the vehicle until the bill is paid or they auction or sell the vehicle to cover the costs to the shop.

Now Arizona:
All the same applies in AZ except the shop cannot keep the vehicle if the bill is not paid.
Here they have to sue for the bill, but the law says a person is allowed to take the vehicle without paying a dime, as they may need the vehicle to make the money to pay the bill and it may cause hardship on the vehicle owner's part to nat have use of said vehicle.

Now being who I am and what I did for a living I knew all this when I dropped my Wife's car off for a replacement transmission and was given a written estimate of expected cost.
BUT when the Wife picked up the car they told her the bill was almost double what the estimate said.
She paid them and took the car home, but when I got home she told me what happened and I promptly called the bank and canceled the check.
Then I went down to the shop with a new check for 200 over the original estimate and told them how they dropped the ball legally, and I was not paying the total they told my Wife.
They told me the trans and shipping cost more than they thought and that was the reason for the higher bill.
I told them since I didn't get a call to authorize that higher cost that it wasn't my problem, but I did understand how it could happen and was willing to add 200 to the original work estimate and if they didn't take that they could sue me and only get the amount of the original written and signed estimate.
In ANY case they could not legally keep the car even if it hadn't already been picked up.

Might want to check your laws by calling your State's Labor commission.