Unknown errors on generation and no refund of credits

Hello i have been using Wan 2.7 uncensored image to video model lot and sometimes, this has happened roughly over 4 to 7 times I think, where the result just gets an unknown generation error and the credits are gone. I paid lot for these credits and even losing one generation worth of credit is big lose. I can't even check my failed generation history they just vanish. Please look into this, it would be great if I could get my credits back for failed generation…