Background: I ride with the LBS owner and a guy that works there about once a week. The guy that works there has been helping me out trying to turn me into a better rider. Anyhow, he suggested I go from my 50-34 chain rings to a 50-36. This is because I run out of gears in my small chain ring and frequently have to ride in the big ring. He said I wouldn't have to change out my 12-27 in the back. Another guy on the ride said he had a 50-36 that he would leave at the LBS for me to try out and if I liked them then I could order some to match my bike.

So I take my bike to the shop and ask them to change out the rings. I go to pick it up today and not only are the loaner rings on there but they put on a who NEW rear cassette and a NEW chain. I just spent $50 for a chain a couple of months ago! They never asked me if they could do this...they just did it! The guy that did the work wasn't there for me to talk to. The LBS owner said to talk to the other guy tomorrow since he didn't know why he changed all the other stuff out, and he let me take my bike without paying anything.

So my question is, should I pay for a new cassette and chain when I didn't even ask for them? What happens if I want to go back to my old setup? This whole thing was just supposed to be a test to see if I like the 50-36 better. If not I was going to go back to my 50-34. They did this to me once before with tires. I asked for x-brand tires and they didn't have them so I said I'd have to figure out what I wanted to go to...when I picked my bike up they had put on new tires that I didn't even pick out....and now, just a couple of months later they are falling apart...he is going to mfg. warranty them for me though...but I don't want those POS tires on my bike!

What would you do?