A/C stops every year in August then works in October

A/C stopped every year for last five years! Took car to A/C repair and they told me it could be Freon leak to check it $129.00. Told me no Freon and needs leak checked! No money for that and left. A/C worked fine few days before was so cold turned temperature up. They did something to A/C because didn't cycle any more! Now have a leak or repair shop ripping me off and disconnected cycling or broke it? How do I check to see whats wrong with A/C? Should I put some Freon in it?