As far as your situation, you may be able to play the game albeit in a limited capacity with a free account: only being able to play in private areas co-op with a fireteam you've invited, no path crossing with larger population, no PvP multiplayer etc. Now that doesn't address not having home internet at all, but given as it's cheaper than having a phone data plan I kinda have to wonder why you've prioritized having internet access on your phone given that you could just get a bare-bones "dumb" phone and basic calling plan and spend the savings on the glory that is the entire internet. Do you not have a computer either? smh