There is no way to get back a deleted text on the phone itself. You can try checking with your service provider/carrier, but once off the phone they are gone.
Now, that said, you can 'try' the following. It is good for other accidentally deleted things (images, etc.), but I cannot say if it will work for this.
There are a few apps/programs out there that 'may' be able to help you recover the data.
A few of the programs you could try would be... DiskDigger, MobiSaver, Android-Recovery and Tenorshare. They are all data recovery apps/programs. There are many others out there, so check around and see which you would rather try. There is also one called RECUVA, that I have heard is free, which you could try.
One important note though...