receiving teh same text multiple times

I have mentioned this before but it is still
going on.  I will receive a text and I
will get the same text multiple times.  I
had one lady who texted me and I got it four times within 10 minutes.  She told me she only sent it once.  This morning I had a lady text me, I replied
back and I got her original text again then her response to my text, then I got
the original text again.  So I got the
original text three times but in-between the last two we had already replied.  I hope that make sense.  Any ideas.  This has been going on for a while.  I have already done a factory reset a few
weeks ago.

Thanks,