How to recover a deleted branch in Git?

On branch compras
Changes not staged for commit:
(use "git add <file>..." to update what will be committed)
(use "git checkout -- <file>..." to discard changes in working directory)

    modified:   filtrar_busqueda/informacion_producto.php
    modified:   filtrar_busqueda/show_all.php
    modified:   funciones/funciones_busqueda.php
    modified:   js/script_publicar_anuncio.js
    modified:   login/info.php

no changes added to commit (use "git add" and/or "git commit -a")

C:\xampp\htdocs>
C:\xampp\htdocs>git add -A

C:\xampp\htdocs>git checkout master
Switched to branch 'master'
M       filtrar_busqueda/informacion_producto.php
M       filtrar_busqueda/show_all.php
M       funciones/funciones_busqueda.php
M       js/script_publicar_anuncio.js
M       login/info.php
Your branch is up-to-date with 'origin/master'.

C:\xampp\htdocs>git checkout compras
Switched to branch 'compras'
M       filtrar_busqueda/informacion_producto.php
M       filtrar_busqueda/show_all.php
M       funciones/funciones_busqueda.php
M       js/script_publicar_anuncio.js
M       login/info.php

C:\xampp\htdocs>git add -A

C:\xampp\htdocs>git status
On branch compras
Changes to be committed:
(use "git reset HEAD <file>..." to unstage)

    modified:   filtrar_busqueda/informacion_producto.php
    modified:   filtrar_busqueda/show_all.php
    modified:   funciones/funciones_busqueda.php
    modified:   js/script_publicar_anuncio.js
    modified:   login/info.php


C:\xampp\htdocs>git stash
Saved working directory and index state WIP on compras: 0f734b8 arreglo de 
cantidades en stock al hacer y rechazar un pedido

C:\xampp\htdocs>git checkout master
Switched to branch 'master'
Your branch is up-to-date with 'origin/master'.

C:\xampp\htdocs>git checkout -b conexion
Switched to a new branch 'conexion'

From here I have been working on the connection branch . At the end I have done the following:

C:\xampp\htdocs>git add -A

C:\xampp\htdocs>git commit -m "mensaje del commit"
[conexion de5a847] mensaje del commit
 106 files changed, 873 insertions(+), 2589 deletions(-)
 delete mode 100644 contacto_qbc/datos_conexion.php
 delete mode 100644 errores/datos_conexion.php

...I've omitted the list of changed files to keep things short. Next:

C:\xampp\htdocs>git checkout master
Switched to branch 'master'
Your branch is up-to-date with 'origin/master'.

C:\xampp\htdocs>git merge conexion
Updating 0f734b8..de5a847
Fast-forward
 contacto_qbc/datos_conexion.php                    |   7 -
 datos_conexion.php                                 |   1 -      

...omit the list of changed files again to keep things short. Next:

C:\xampp\htdocs>git branch
  compras
  conexion
  errores
  errores2
  errores_fac
  history
* master
  purchases
  purchases2
  qr
  sales2

C:\xampp\htdocs>git checkout compras
Switched to branch 'compras'

C:\xampp\htdocs>git status
On branch compras
nothing to commit, working tree clean

C:\xampp\htdocs>git checkout master
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)

C:\xampp\htdocs>git branch -d compras
Deleted branch compras (was 0f734b8).

And here is my mistake. As you can see, at the beginning in the purchase branch I add several files and use the ´git stash´ command if I´m not mistaken this command is used to temporarily save the changes in that branch, and I thought that when trying to delete it it would not let me. Does anyone know how to recover that deleted branch?