Faulty battery after 1 month

So I got given a twisp by a friend of mine for Christmas and its been little over 1 month snce i've been using the new device and been having problems i charge it and it does not switch off constanly burns. i have gone through more than 14 coils because of this problem and lost so much money at R56 per coil and working at a minimum wage job it has a great affect on my finances. In the mean while my the friend who has given me this has moved over seas for work and I do not have her new number yet so I can't get the orginal slip from her. How do i fix the problem? i have been at a kiosk and was very upruptly told i need the slip and nothing can be done for me even though i have been using this companies products since 2012. The one guy at the stand can back it up. I am very dissapointed in the manner i was treated by a blonde girl that was working there but even more the product that is suppose to be an improvement on the previous.