I have a Samsung Galaxy bought a few years ago and I haven't downloaded any of the updates since buying. Do I need to do this and can anyone explain to me (in simple terms if possible please) how I can download these updates without losing my credit as a PAYG? A relative tried this but wiped out my credit of almost £15.00. I have now added £10 but am worried in case that should disappear also. Secondly, I am not sure if this second problem is because of not downloading up to date software, but if I am sent a text message it is duplicated to me and I get either get the second, same text, immediately or the second one comes through a few hours later. I am with Tesco Mobile. Any help would be most appreciated.

