LG G3 problems

I purchased the phone in February 2015. In the first week i had to replace the battery. After 1 month i started having a few issues. Then after about 7 months my email wasnt working and i couldn't open new or old emails. Each time i got a new email it would delete the older ones. I took it to vodacom and they couldn't find the problem and told me it was a sofware issue and i must send my phone in for a sofware upgrade. When i got my phone back the issues were still there and my phone keeps telling me i have viruses. I now can't open or download email attachments so a week ago i went to Vodacom to rectify it and they couldnt find the problem and told me i must book it in. I reset my phone now and the issue is still there. I have emailed LG customer care and i have had no feedback.