I tried debating and he said that his 10 years of experience and training account for something against your internet research.
"Internet research"?
The Internet is merely the method used to access the information, and is irrelevant.
I would
ask these questions:
1) How are permitted routes defined? Where can I access this information?
2) Is it correct that the shortest route, plus any routes within 3 miles of this, are valid routes? If not, please tell me what the rule is and where this is documented.
If you merely tell them you have looked it up, then some staff will accept it, but some will not. Asking them to look it up can be more productive. Sometimes they are unwilling or unable to look it up, in which case I would ask them some further questions to determine if they have ever been made aware of the rules.
Unfortunately some staff just make up the rules as they go along - see the FCC peak restrictions thread!
I am fortunate in that the TOCs I use the most (TPE, EC) have staff who very rarely make things up, and if they do, Customer Relations will apologise and resolve the matter (I've hardly ever had to contact them, to be fair). If I used SWT/FCC I suspect I would have to contact Customer Relations a lot more often.