Gst regn. thereshold limit

Dear Sir/Madam,

I have a doubt on GST registration:

Im migrated from Services Tax to GST with my threshold limit is exceeds 10 Lakhs.

after that now GST threshold limit is 20 Lakhs and proposed new limit is 40 Lakhs.

Now my turnover not exceeds 20 Lakhs what should i do, whether continue as GST registered dealer or surrender my GST

Thanks & Regards.