Just remember that for every measure you take somewhere there is a countermeasure.
So far we just have them on Text Me and have only seen a couple of texts that were truly wrong number instances.animal jam.
Also, in addition to the standard display ads and in-app purchases, many companies are testing new marketing methods that meld advertising and content, such as's "promoted chats" (in which brands text with users).
Some track and collect user data -- including location -- for marketing purposes.
I don't know a lot about i Phone's or the apps for it but if you talk to Apple (at a store or call them) or your phone carrier they can probably assist you.
With Android, you can still talk to the carrier for help.