Where do I stand?

[ShaneyB]

Hi all,
Bought a B4.1 RTR on Thursday Feb 16th, used it with my son 3 times since and the steering is still locking full lock right. This has happened twice out of the 3 times I've used it and I'm not happy. My son went to use it last night, turned the transmitter on, waited, turned the car on and sure enough it went to full lock right. This happened the day I bought it so I took it back to DMS the following Monday and it didn't happen (typical).
We love the car but wondering if we have bought a dud? I don't think that I should be changing servo's etc. on a brand new £300 car so should I take it back and get the car replaced?
My son is gutted and fast losing interest in a hobby we haven't even started properly. I think 25 minutes driving (max) in 2 weeks due to a problem I've had with the car since day one isn't acceptable.

Any advice please?

Thanks in advance.