data throttle question

[inthegalaxy]

I have a Samsung galaxy s3 and I have unlimited data that is slowed down after 5 Gb. I've tried several apn numbers but none seem to work with the s3. If someone could tell me how or sen d a link with help.

P.S Im not a big data hog I just drive truck 6 days a week so I use around 8-10 gb a month.