We can help with that; if you want to claim your money-back guarantee, please contact us here; once you've sent us a message, you can send your TENS machine back using the satchel inside your hire. 

Please remember that the money-back guarantee is for completely untouched hires (aside from retrieving the return satchel). If you set up your TENS, test it, use the batteries or open any of the accessories, it will make your hire ineligible for the claim. You can find more information on the eligibility requirements here.