Ip conflict, high chance of privacy leak. but co compensation

sir, Though I inform them several times, They took it casually after 3 months It was cought that someone name sankha subhra used my line with same MAC (by hacking). atlast they cought them and disconnect them . Now I am dare that My personal data can be compromised so I may have to change all my details passwords bank cards. I request them to change my internet IP, conpenset me. and give me a reliable connection like fibre optics that is most common now a days. but they didnt pay any attaintion to it. even I mailed them at : [email protected]. but they didnot response