Didnt provide the service after i paid

I purchased 7 driving lessons from Rolling Stone Driving school over 3 months ago. they had an advert on Groupon. I called them to enquire if the deal was still on and they said it was. they said I could pay directly to them. I paid in full and they only came for 3 lessons and that was it. I called them and sent them messages but they will either give excuses or not even come back to me. im so disappointed. 3 months down the line, I still haven't finished my lesson yet I paid in full