I Hate to say this Sir, but she never appreciate all your efforts aside spending £ for the visa/airfare and just in 2 weeks,she never had second thought of going back in PI, just a friendly advice, try to refuse or say no, if she ask for money, or financial support, when you say she isnt coming back, that sounds to me she end up the relationship, move on lwe only had one life to live, dont waste it by others making us upset
Best wishes and all the best in the future