The intention of government was to bring every business in tax net. Looking at your case or many other service providers who hardly have more than 10 lakh revenue are made to register under GST.
If we go as per the GST provisions, a person with turnover less than 20 lakhs need not to register under GST.
Of course your revenue is well below that limit. Still you have registered for GST.
Here it is not government rules but specific corporate policies that companies have made you to register for GST.
Can you deregister from GST?
Yes, you can apply for cancellation of certificate at any time.
But before you do that you have to refer to the policies of companies you deal with. For example, in my case few companies does not add vendors without tax registration.
Should you cancel the registration?
I do not think you should cancel your registration. None of MNC or corporate houses deal with unregistered vendors.
Why companies avoid unregistered vendors?
Because of their policy!!!
Now coming to GST, not only MNCs or Corporates, even small businesses who are registered under GST are avoiding any kind of dealing with unregistered vendors.
The reason for this is REVERSE CHARGING MECHANISM (RCM).
Believe me once you cancel your registration, you will lose clients or you will be bound to invoice company through some third party (pass through arrangement).
Now coming to formalities, unfortunately as a service provider you cannot opt for composition scheme.
Once registered under GST, you will have to comply with all formalities.
Note that non compliance can lead to heavy fines.