Sometimes my friend does this and its annoying and i dont understand it?

my friend will invite me over and when im over theyll tell me they have a plan for us to go to a nearby town(cant name it) and go cinema. thing is they ob have planned this and take for granted ill go with them without asking. and when im like i duno dont really want to theyre like oh okay.....but itll be fun well see what well do later...and then try get me to go again. its really annoying why would they not tell me on the fone? its like they dont care if i dont want to go aswell?