The inserts are 100% guaranteed to function as claimed if used as instructed in the page of instructions and for healthy feet. If the inserts don't work please email me at service@killerheelscomfort.com and tell me what the issue is. If I can help with clarifying the instructions I will do so, but if I cannot help you then you should send the inserts back to me to the address of my business and your money will be refunded by reversing you credit card or Paypal charges.
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