Help with samsung phone

Hello Guys my wife has just received a replacement umlocked sim free samsung galaxy note 4 SM-N910F. This is a replacement for a EE branded note 4 in the UK. She lost her last one.

Anyway when shes sending a long sms message the phone converts it to a mms and were being charged mms messaging by EE. The last EE branded device didnt do this when sending long messages,. Any idea how to fix this please

Pretty sure I had this problem on a phone a few years ago (memory bad though can't remember which one?) think I ended up downloading Handcent from the App Store & using that. There was a setting in there to prevent converting to MMS when the stock messaging app did it automatically.
More info here
Why Long Sms are getting converted in to MMS ! | Android Forums
Good luck mate,
HH.

Had the same problem and the way HappyH describes worked fine for me as well!
Give it a try!