deployment – After deploy the webpart is not updating?

We deployed a webpart but it keeps old html. And ı only changed a text in a div, but i cannot see the code changes in the site. Also, everything looks perfect . I mean visual studio shows the deployment is successful, we tried powershell to deploy, but it shows deployment succeed too, also in Central Admin it shows deployment succeed too. On the other hand, we tried to Retract solution , Remove Solution and Add Solutuion but it is not working.
So, How can we do this?