You have to first go through the agreement and conditions for appointment of stockist/distributor and find if there is any restriction clause agaisnt the company.
If you are sure that the company has violated its own condition you may file an injunction suit agaisnt the company in this regard seeking to restrain it from appointing any other stockist till the termination of yor present agreement with the company
By the way hen is the contract getting terminated, is it yearly renewable or how?
Holding the contract for a long term will not bestow lifetime interest in the company's contractual agreement with you,
The company may decide to change its policy anytime and it is not bound to your dictates.
Therefore consult a local company/civil law practicing lawyer, discuss all the issues properly before you would like to initiate any legal action against the company.