Welcome to Android Central! Which Samsung phone do you have, running what version of Android?
I'm not sure I follow what you're saying. So you uninstalled your old WhatsApp from your phone--when you tried to reinstall, are you saying you tried to do it via the Google Play Store? What would happen when you tried to open Play Store--an error message? Does the phone freeze? Does nothing happen at all?
Does this persist even after rebooting the phone?