Sony Ericsson Z520 / Z525

since the past day, anytime i send a long text message, the recipient receives the message with (...) and then the last few words of the text message. when i receive a long text message, i receive the (...) with the last few words ofthe text msg as well. These are just basic sms text messages. when i go to my inbox, the envelope icon is "split" in half, indicating that the text message has been broken or cut off somehow. This is very important, does anybody have any solutions or advice? it would be GREATLY appreciated!