I feel for you. I had my first pc from Mesh over 7 years ago and had similar problems, but i never ended up sending the computer back to them. I was too afraid after the experince i had to give it back. Luckily for me, there were no hardware faults, but as i was new to computers i was clueless to what was a software and what was hardware fault.
When you get the pc back, keep it! If a dvd drive goes bang, then suggest to Mesh you send the dvd drive only. Ok, so you will need to go in there with a screwdriver, but its better than being without the thing. They obvioulsy havent changed much with theri customer services, and please, only as a last resort, talk to a technician in Mumbai. They're not technicians, they're just guys with no particular training or qualification in computing, they just have a bit of paper in front of them, reading out things like, Remove this, remove that, unplug those, carry your pc out into the garden and plug in direct to a telegraph pole, and then ask if they can help you with anything else on this fine day! Hehe, you got me going now.
If you can post your problems here in the help section, id prefer your chances than dealing with Mesh. If something goes wrong, and its technical, send the part back only. If its software and driver issues, then HERE is the place to fix those. Good luck, I will say one thing though, my pc containted quality hardware, they're products are great, when they get to you and work fine