The reason for this is because you have to change some settings on your phone.
You can automatically change your settings by texting the word settings to 2020, if that fails follow this short guide :-)
If you have set up the settings properly then it should be something like this...
Name : giffgaff
MMS proxy: 22.214.171.124
MMS port: 8080
To manually change the settings above go to...
Settings > Wireless & Networks > Mobile networks > Access Point Names (APN)
Then just restart your phone
If still nothing then turn your flight mode on and off.
Please note: MMS messages cost 16p to send and it not covered by your goodybag.
If still no luck... check the giffgaff network coverage website by following this link below.
Scroll down the page and put in your postcode and select data from the box and click enter and it will tell you.
Please note the information on their updates every hour.
Hope I helped
Hi there and welcome
There are guides for everything you need, just need to search for them
As it's an Android phone try here: