I only can presume that they use there own money, they open a bank account for you the money is shown in bank book, I used the agency called key visa in pattaya.
I got my retirement visa today, agency does everything for you, open bank account, transfer funds for you, you don't need to have the 800,000.takes 3 weeks, they do everything. I paid
I arrived in Thailand on 30th November last year, got 45 days, then extended at immigration for 30 days, flew to Vietnam for 3 days, came back, got a further 45 days, then extended at immigration for a further 30 days, yesterday flew to Cambodia, came back today, got another 30 days, so I now come in three times by air no problems at immigration.
I now intend to apply for a retirement visa.
Just wanted to share this as many people said you cannot do more than two flights.