The only time minx have not lasted on fingers in my experience is when they are scratchers(causing it to peel back from the free edge), have hands in water a lot, or if over stretched when applied. I did them on myself ages ago and when pulling taut I pulled them too much which caused them to shrink back and peel at the free edge after being filed. I have found with the fingers I have minxed that they last longer on shorter nails IMOE!
I wouldnt myself re do for free as they are not designed for the longevity of the toes due to wear etc. Did you advise the client of how long to expect them to last and that it is upto x days? I always say they are an occaision treatment and that I can not guarantee the length of time they last as it is down to there after care. The ones I have done have lasted upto 10 days, the least being 2 (the scratcher). Not sure but maybe if they were applied over enhancements that may be a cause?? I'm not sure as I have only ever applied to the natural nails.
If you want to redo them, maybe offer them at cost??? hth's:hug: