Failing Marin Chainring/crankset

Gweilo_uk

I thought I'd post this to the MTB forum as well as the equipment forum in the hope that I might get a specific response from this forum, or at least make people aware of a potential issue with Marin's chosen chain rings. I then realsied I'd posted it to the general section rather than technical ... oops

I have had a 2006 Rock Springs for a VERY short period of time, the bike has done about 100 miles so far, and to date the front crank has F***ed up twice. Once the whole crank was flapping around in the bottom bracket leading to the chain jamming and the chain set being replaced. The second time ehe middle chain ring seems to have bent in use leading to the chain jamming between the middle and top chain rings. This has happened after 40 miles the first time and then less than 30 on the replacement. I believe that the chain set is maufactured by deore

My question's are:

1) Is this a common fault that people have experienced before

2) do I:

a) demand a new bike
b) let them fix it again with the promise that one more failure = new bike
c) demand an immediate full refund and go buy a bike that works

Any advice greatfully received

Angry of England