I agree! I'm rather bemused by this whole thread actually!
To the OP, if you are a severe nail biter I suggest you go to a reputable salon and have your nails soaked off and replaced with a liquid and powder or hard gel system. Some technicians will infill they type of nails you have until they have grown out.
Going back to the salon saying you didn't get what you asked for is not a solution. In the type of salon you went to they call the powder a 'gel' as it forms a 'gel'. It just isn't a UV gel which is, presumably, what you meant.
£30 is not much to pay for a full set of enhancements. Highly trained technicians using good quality products will charge more than this (I'll wait for all those disagreeing with this statement :lol
but cost doesn't guarantee a good service.