It's pathetic when it's a legitimate request for the girlfriend yo visit as a holliday and get rejected when the UK is full of illegals including many serious criminals, absolutely pathetic, the country is a joke nowadays.
From what I have read on here from similar questions I think its very involved and very difficult to get a tourist visa to the UK for your Thai girlfriend, it might be easier to her a seat in a rubber dingy from a French beach.
There are so many different quoted answers about transfers, where I live the immigration needs to see the prefix FFT on the transfer transactions in your bank book, probably different at other immigration offices ???