The inserts are 100% guaranteed to function as claimed. In the event that something is wrong with the inserts or the packaging - for example there may be a mistake in the packaging and there are two left foot inserts and none for the right foot - the inserts and the package should be sent back to Killer Heels Comfort.
Please send an email first addressed to me, Virve Georgeson at the email firstname.lastname@example.org and let me know what the issue of concern is and if it can be fixed by you I will instruct you on how to fix it, however if it cannot be fixed please send the inserts back by regular post and they will be replaced. I will provide the physical address to which you can send the defective inserts or defective packaging.
The inserts should be used only as instructed as inserts to be put into shoes to provide comfort. The inserts are not a medical device to correct foot problems. The inserts are intended to be used for normal healthy feet and in shoes that fit properly as per standard shoe fitting practices as recommended by podiatrists. Here is some footwear fitting advice from Podiatry National
Although there is a way for the inserts to be made so they can be moved from shoe to shoe (see FAQs) this will compromise their effectiveness in holding back the foot for any length of time and their function of providing optimal comfort is then not guaranteed.