If a customer get the work from seller and in the end he cancelled what should seller do?what should be his action? Can he take him to court?
Too many unknowns to definitively answer the title.
However, with regard to:
what should seller do?what should be his action?
You can partially protect yourself from these situations by taking part-payment up front. e.g., you might request:
- 30% to begin
- 30% at an agreed mid-point
- 40% when the project is completed/launched
That way, if things turn bad, you ideally have at least something to show for it. So, the seller's future action should be to adjust payment terms before commencing the next project with any client.