Please I keep trying to send message with my mtn line but it keeps saying **send failed**

I can't check my balance or even use the data I just got because my mtn line keeps sending me the same massage that my line has been temporarily blocked, please I need a way to...

My mtn , does not send sms and it's a challenge to me.pleqse I need an urgent response

Messages not sent.

I've been trying to send messages on my MTN line to no avail, I've checked the message centre no severally and it's correct, what can I do ?