So seeing as I'm a bachelor, I've been thinking of switch all my meals to prepared meals. The reason is cooking is such a mission for one and most of the time I end up having no dinner at all. The food I buy monthly tends to go bad.
Will it be healthy if I do this and have anyone else done this?
I have done this! And I had to change a bit

I ate their Chicken Korma/Butter Chicken/Tikka Chicken for about 6 days a week for a couple of months. Not healthy ... I had dark rings under my eyes as my liver started to complain. So I still buy lots of Woollies, but I try to get as much variety as possible and things are going great. I am pretty sure if you make sure you have lots of variety (including different veggies and fruit) you should be fine. Woollies actually makes it relatively easy to have 2 o 3 types of veggies and 2 or 3 types of fruit every day -- which is something that is very difficult if you have to cook for yourself (e.g. eating one half a carrot, one stem of broccoli, half a mango and eight of a melon does not work if you cook for yourself unless you are willing to throw lots of stuff out). I travel and stay in hotels and guesthouses a lot, and I must say that all things being equal, Woollies is probably a lot better than eating in restaurants everyday.
But I must admit that I also recently discovered that the entire "fresh" vs. frozen veggies argument is a bit of a sham*. So as backup I also keep frozen veggies and fish in the freezer compartment at home. Fast and easy to make.
Of course, given all of this - I am sometimes upset that I don't cook more. I think cooking your own food is probably the best thing in the long term, because the act of cooking makes sure you think more about food and therefore make more informed decisions. And it can be very satisfying hobby!
*The sham is that fresh actually means just picked. The "fresh" stuff you can buy in Pick 'n Pay and elsewhere is a couple of days old already , and nutritionally not that much different from frozen veggies. Frozen veggies lose nutrition because they are blanched before they are frozen, which is something that will happen pretty much anyway unless you eat everything raw out of the ground.