I purchased this item from CAMBRIDGE SCIENCES LIMITED via Amazon. after few days I noticed that the device started to freeze for few seconds, then it froze completely and eventually had to re-boot it. I contacted the seller and told them about the problem, they offered to fix it or replace it. I wanted to get refund as I didn't want to take a chance in case it happens again further down the line. I booked a courier company as I wanted the item delivered next day and safely. When I queried when I would receive the refund they told me in 72 hours and that's it. It turns out that the decided to pocket £20 and refund the rest. Amazon has nothing to help, never told the reason why the seller wanted to keep the £20, it wasn't until I contacted the seller they told me that the box was damaged and therefore they decided to deduct £20. Not once did they contact me since receiving the item that the box damaged. Also they send 7 point conditions in which the item should be returned, having already complained that the item was defective/faulty, surely it doesn't make any difference if the the device has got finger prints all over it, surely they were going to investigate upon receipt of this item before re-selling it on. I suspect the general idea was to place it back shelf as if nothing ever happened and sell it on to another customer. I am waiting photographic evidence which they claim they have, before taking them to small claims court to recover my money. I would avoid this company at all costs. I have purchased many items online over years and never had the retailer/seller trying to pull a fast one like this company is trying. Needless to say I won't be purchasing anything from Amazon again.