I could be wrong but you might have an APN issue.
Have you the below settings correctly configured:
Fizz APN settings are: APN: mobile.bm
MMS proxy: mmsproxy.mobile.bm
MMS port: 80
APN type: default,mms,supl
Other fields should be filled by default; if empty, they are not mandatory.
Steps to follow for configuring the APN can vary from one phone to another. example:
Android: Settings → Connections → Mobile networks → Access Point Names → APN