Hi @hurab
If I understand correctly, you would like to remove a refund that you have done by mistake, but just to keep your records straight and not to actually reverse the refund and charge the customer again for it, correct?
If yes, you can follow the following steps to remove the refund from the order;
* Under Status, put the order On Hold and click on Update;

Link to image: https://cld.wthms.co/VD3ok8
* Once the order is On Hold, you will be able to click on the small x
on the refund line item to remove it. After that, you will need to click on the Recalculate button;

Link to image: https://cld.wthms.co/7NHWoT
* Now you can put the order back to the status it was before and click on the Update button and the refund will be removed and the totals will be correct again;

Link to image: https://cld.wthms.co/uAx9qs