Your GF's position.
Please do not waste any more of your money applying for visa's for the United Kingdom, if your GF is legally married to a.n.other in the Philippines, then by virtue of this, you are not able to apply for a marriage visa, (a spouse visa is out of the question since you are not married)
If your GF'S Visitor visa was declined, a tourist visa does not attract the right of appeal, unless the visitor is a relative of the person in the UK who is presently settled and living in the UK.
Although the Entry Clearance Officer is under no obligation to give a reason for the refusal to issue a visa, it is more than likely that the reason would be best described in that your GF's reasons for visiting the UK, represent a clear and present danger of flight risk.
If this is the case, then the Entry Clearance Officer has decided based on the information on the tourist visitor application, that he or she is not satisfied that your GF intends to return to the Philippines at the end of her stay, one of the ways in that this often happens is when the tourist applicant names a potential relationship partner as her contact in the UK.
I am sorry to hear your GF'S Visa has been declined, although this may involve long term pain and waiting for circumstances to change, my advice to you is to either assist your GF to obtain a Legal Anulment of her marriage in the Philippines, a long and lengthy and expensive process.
Or quite simply, if your desire is to find a partner from the Philippines for the purposes of companionship akin to marriage, then find a single lady to fit the bill, there are millions of them.
Best of Luck.
