Thank you for your follow up.
I cannot comment on your specific case, but generally, even if there is a billing issue or one party think that the other contracted party is overcharging or engaging in excessive / unauthorized billing practices, the party that is claiming such billing issue cannot unilaterally terminate the contract without first addressing the issue with the deliver company and attempting to find a resolution.
So, generally, the first step would be to consult with an experienced local business law attorney who can review the contract and all related facts and can start by sending a letter to the pharmacy to cure the breach of contract and also to put the pharmacy on notice that if the issue is not resolved, that a legal action, such as lawsuit based on the breach of contract would be filed.
If the pharmacy refuses to negotiate a resolution, then your local attorney can determine if it would be feasible to file a lawsuit, since litigation can be lengthy and costs many thousands of dollars in legal fees and court costs and if it is feasible than your local attorney will be able to file a lawsuit on your behalf, to seek any actual damages that resulted from the breach of contract.
You can find an experienced and skilled local business law attorney by using this established and reputable attorney information / referral websites:
When, choosing a local attorney to represent you, it would be a good idea to choose someone who has a practice exclusively dedicated to business law, has at least 10 years of experience and handled similar matters and also regularly practices before the court located in the jurisdiction where your matter might be heard.
I wish you the best of luck!