BUt then again they should have it ready made to accept any amount without any limitations
I'm sorry Dev4vip but I have to disagree with you there - in a sense its better.
Firstly there is the security - If I was running a website like 2checkout, I would almost certainly want to be informed if a transaction on that scale was going to be place so that I could ensure that the security between the transaction was extra secure and went flawlessly.
Next there is the chargeback risk - The business would need to make sure that It had enough money in reserves to cover the risk of a chargeback on that account - could cost thousands.
Finally there is the fraud risk - 2checkout would need to perform quite a vigorous fraud check to ensure that it was not someone else's card was not being used. For a transaction on that scale you would want to put a few staff on standby before and after the transaction took place jsut to be extra sure.
I'm sure that any company which was dealing with a transaction on that scale would want to know about it.
In a sense it is also the OP's own fault because who in their right mind would do a transaction on that scale through a web merchant account. If it was to be done online, I would make sure it was being sent to me either via bank transfer or held in Escrow awaiting immediate transfer.
It could have also been done by a registered cheque - in this case I would only accept if it was sent by secure courier and with a cheque guarantee card. even then I would wait until the funds reached the bank and had been processed before shipping the goods.
The maximum transaction we will handle online is the sum of £1000 (approx $2000) even then rigorous fraud checking is carried out and we will inform our merchant provider prior to it being carried out - its just something you should do!