Transferring Partial Interest on a Property

My mother and I bought My primary residence together. The documents at closing were incorrect, they did not have my name on the house. The title comapny told us they would correct it, but they did not. We would like to add my name to house but still keep my mother on the deed, since she is on the motgage. What would be the best way to accomplish this? I have called many title companies and no one called me back. I spoke to my county and they told me they can not tell me how it needs to be done, just that if it is submitted incorrectly it will not be processed. Any guidence you could provide would be greatly appriciated.