Why can't I get service on my iPhone 4S?

I just came back from a trip to Phoenix. I turned off my mobile data and turned airplane mode on. Both of them remained that way until the trip was over. I was there for four days. I came back to Winnipeg and turned them back to the original settings. It's been a day and I still don't have service. I tried turning my phone off and then back on again, turning the mobile data off, and turning airplane mode on. None of them worked. I don't know why. My brother has service and he told me to try these steps.

My carrier is MTS. Can you please help me get service?

Could humans live on a planet with more gravity?

I have been hearing alot about the Gliese system and they are talking about humans living there some day in the very distant future, but they also say these planets are about 6-8 times the size of earth. They are most likely more massive then, causing stronger gravity, 6 times the gravity here! That would mean that if I weighed 100 pounds here, I would way 600-800 there! Is there something I'm missing, don't we need earth like gravity, or less to survive? It seems that with that strong of gravity our blood would be slowly pulled from our upper body and into our legs. Thanks!

Sorry if my typing is weird this is on my IPhone and I have autocorrect off lol.

IPhone 4s or Samsung Galaxy Victory?

I can't decide whether to stay with my 4G LTE Samsung phone or change it to an iPhone 4s which only has 3G. Help?

Added (1). So iPhone or Galaxy?

Can I buy an iphone without contract?

Many carriers advertise that the iphone cost under 300(generally) but WITH a 3year contract (on selected plans) which means that, yeah I get the iPhone at a low price but I'll also have to pay the monthly charges which are at least 60 $.

Therefore, I decided to buy it without contract (cause it will be less expensive) but I wanted to know if the carriers will still have other monthly plans…

Added (1). Will they let me buy the iphone at the normal price and offer me cheaper plans?