You have to let us know what do you mean by full refund? If you are beyond the freelook period of 15 days, you will likely not be entitled to any refund of premiums. If you are looking at surrendering, there are surrender charges, as insurance is a long time commitment. Hope you let us know exactly what do you mean.
As a fresh grad, 300k CI coverage is good enough. You might want to explore life or term policy that cover about 5 times of your annual income should be fine. The only time that you need to revise your coverage is when you have new liabilities and responsibility (new house, first child etc)