poor service

I would like to express my dissatisfaction with whom ever runs this business. i moved in to a new development and took on the service in June this year 2024. The technicians came to install the system, 2 months down the line was an issue with the alarm, the Andre Koen and his team came to sort it out after i struggled to log the request for someone to assist. about a week ago i called them to let them know the system trips and often wont arm. Andre Koen and his crew and told us that the battery that they installed, and told us that it will last for years and it serves as a backup when the power is off. Now they told us we need to replace the battery for R450. Firstly this battery is only 6 months old, and needs to be replaced at my cost? they told us someone tempered with the battery, andre and his crew are the only people that have been to my house and worked on this device. if someone tempered with the system then why is it my fault that the battery that is state of the art packed up?