In all fairness most warranty terms and conditions state that the supplier will not be liable for loss of productivity, earnings et al from a 'broken' machine.
I think personly an apology is not good enough, at least not at this stage. However legaly I am not sure Mesh are required to give you anything.
It might be worth speaking with your Credit Card company if that is how you brought the PC. They can put far more pressure on Mesh than you. Plus they should be able to give you some advice on what to do. You could also try the Forum Ed, he - or is it she? - has I believe helped people out in the past.