Pay the GST tax, though my turnover has not crossed 20 lakhs?

Hi, I am a small security agency owner and my transaction or turnover is not more than 20 lakhs per year, however, I took the GST registration without knowing this fact that there's liberty up to 20 lakhs. Now, since, I have got the GST registration is it just that I need to pay the GST tax, though my turnover has not crossed 20 lakhs? Please help.

GST registration is required primarily if your annual sales are more than Rs. 20 Lakh. Even if your sales are less than Rs. 20 Lakh, we suggest that you voluntarily opt for GST registration because:
1.You will not get any tax refunds on purchases (e.g. if you buy goods worth Rs 1 lakh in a year, and tax rate is 28% – you will lose tax refund of Rs. 28,000)
2.You cannot sell outside your state
A person can get registered voluntarily under GST in terms of sub-section (3) of section 25. All the provisions will apply to him as they apply to a registered person.
# Registration can be cancelled in 2 scenarios:
1.When the taxable person wishes to voluntarily cancel his GST registration.
2.When the proper officer, on default by the taxable person, moves to cancel the GST registration on his own motion. This may be when the person is not doing business from his declared registered place of business or if he issues tax invoice without making the supply of goods or services.
Regaads,
Amit