Very very bad service

It is very sad that Assesstech was sent to me to assess the inventor by my insurance. Their technician by the name of Ronald open lithium battery that was only 2 weeks old even after i told him that the battery it is still new and the issue is with the inventor. Now i am stuck with a battery that has no warranty and they claim that they are accredited to open and access devices and when i ask for that Mr. Filipe Dos Santos said they will write an email to the shop owner. I have never come across such a bad service in my life and i really do not want to work with them anytime in the future because they hide behind emails that they end up not responding to. The only thing that i requested from them is the warranty and they can take away the battery that they have tempered with its warranty because my claim was never about the battery