That's going to be tough. Most internet packages that you get on a fixed phone line require that you have a minimum contract of 12 months unless you go on the pay as you go option which gives you dial-up speeds (56kbs).
Your only option is to get a USB key with prepaid internet credit and that's going to cost you Rs2,999 and you get 1Gb worth of data. You're going to have to purchase additional data allowance depending on your needs as follows:
1GB - Rs499
3GB - Rs999
5Gb - Rs1299
That's with Mauritius Telecom -
http://www.orange.mu/internet/internet_e...Downloading and playing games online will eat your data allowance very quickly, so I'd advise against that and you're supposed to be making the most of your time in Mauritius (you'll be on holiday, right?) and not stay "home" in front of a computer.
You can find more information on internet facilities in Mauritius here :
http://articles.cleverdodo.mu/internet-s...Any questions, let me know :)