Hi all!.. i recently got a galaxy s5 and optus sim card with two gigabytes of Internet per month ,for some reason when i use youtube for a 30 second video it can take as much is 20 megabytes? i called optus and they advised me to turn off the 4G option which i don't mind doing , however even with only 3G it's still uses as much as five megabytes just for a 30 second video , this didn't happen with my galaxy s2 with vodafone sim card and only 1 gigabyte per month so i don't understand with such little usage how i've got such high data usage....i appreciate any help i can get in this matter ...thank you