The scam comes after you've done the Embassy 'stuff', which you clearly can't even recall the correct terminology and the documents.
4 years ago, a friend of Ireland had arranged to marry his Thai girlfriend of 10 years in Hua Hin.
Arranged a big reception party with 12 of his family flying in from Ireland for the event.
He entered VE 2 weeks before the planned wedding date and planned to stay 4 weeks.
Outside the Ireland Embassy, he was approached by a 'tout' offering to get his documents translated and legalised for 10K.
A week later, the 'tout' stated there was a problem with his documents, but it could be cleared up for an additional 10K.
2 days before the planned wedding, he contacted the RTP on the advice of his fiancée.
The RTP tracked the 'tout' down through his mobile number, but he claimed no money had changed hands (all cash, no receipts) and demanded 2K to return his documents and passport. The RTP advised him to pay the 2K just to get his documents back, as it was one word against another.
They had the ceremony, but no time left to now get the docs translated and legalised, as he'd already stayed almost 5 weeks.
He departed, paying a 6-day overstay fine.
They married a year later.
Another friend who didn't listen, only last year employed the services of a 'tout' outside the British Embassy to translate and legalise his documents, and that was the last he ever saw or heard from him. RTP weren't interested.
If that's scaremongering, then so be it.