Bought my Samsung S4 in August this year and was very happy with it until last month a Samsung update caused the contacts on the phone to freeze. Overnight the phone completely stopped working and I was left with a black front screen and no way of turning the phone back on. I initially sent the phone to Samsung to be repaired as it was still within its warranty period, however, they returned it to me stating the warranty was void due to non approved firmware being installed. Not being very technical myself (my last phone was 6 years old), I phoned the dialaphone service centre who informed me that this could not have happened unintentionally so knowing that I had not installed anything I then sent the phone back through to Dialaphone to be repaired or replaced. Three weeks on and I have now received a phonecall from Dialaphone to say my warranty is void due to an unauthorised repair (Hmmm you'd think at least they would come up with the same problem!). Now, I know the only people who have looked at my phone are Dialaphone and Samsung so no unauthorised repairs - who would be that stupid when the phone is still under warranty anyway! After a very frustrating phone call to customer services who basically said it was up to me to prove that I hadn't done any of these things to the phone (wouldn't have the first clue how to go about that by the way). I am now in the process of writing in formally with a view to going to the small claims court if I get no joy. I can't see that a judge would expect me to pay for what is obviously a faulty phone. I for one have learnt my lesson the hard way - beware.