Oh you were trying to go on Tab L and get a cheaper price on the iPhone. You - can- keep your plan but you'll have to use Tab M, which is a max $300 subsidy. You'll just pay an extra $5 for the Tab charge until it's paid off.
No, I was told, even with the increased tab, that I could not keep my 6gig data plan with a new iphone. Which is why I still have my lg phone. The most I could have was 2gig plan and the extra 25 bucks did not even include the extra cost for the increased tab.
I had same issue Alacrily! Bottom line as far as 6G plans go, we have the best. I found it in my best interest to go with Moto G on small Tab and keep the 6G plan. Otherwise I'd be paying over $100.00 for 6Gs and adding extra to pay off "up graded" phone.
The S3 is free on Medium Tab still too. It has microSD and a removable battery plus it's newer than the S II X (so you'll be getting 4.4 soon). You'll also be able to keep your plan; just add $5/month until the Tab is done. :)