I was in Lyon 8 days ago and it happend to use one of these bikes. First of all there is no english explanation on the terminal. It will ask you to put your card (I used my Maestero) and enter the pin. They will give you a bill in which it has been stated (of course in French) that they will not get the money unless you use a bike. Then you must enter a four digit code and re-enter it again to get a blue card which is valid for seven days and then you swipe the card and there will be a screen in which you can choose a bike number to make it free.
I failed to enter the code at the first time I tried. So I just put my card again, got the bill and with some help of two french guy managed to have a bike. And I repeated the procedure for my friend also. So overall I used my card three times and got three bills but I used two bikes.
BUT when I come back home I saw they took three 150€ from my account and as I fax them or email them there was no answer! I called them but they cannot speak English! Finally one of my friend helped me to call them. They said I must take the first 150€ from my bank and they will return the 300€ after 7 days (As the card expires) which they have not done yet even! Funny is the bank said it will cost around 100€ to get the money back!
I do not like to use bad word but I really pissed off and they spoiled all the fun I had in Lyon. Wish me to have my money back!