Hi - I agree with joanmalaga - your problem is with the lack of a Habitation Certificate, not the fact that your apartment is a Touristic apartment. There are some restrictions on touristic apartments, namely that you cannot register this as your permanent home (cos they are meant to be rented out) but you only need to rent it out once per year to stay on the right side of the law. You can buy and sell these apartments, but you should point out to any buyer that it has this special status.
The Habitation Certificate has been discussed on the forum many times and you can search to see more detail. However, in essence, the certificate should have been applied for before the property was purchased and it proves that the council is satisfied that the property has been completed in line with the planning permission which they gave for the build.
You should not have been allowed to complete, nor should you have been allowed a mortgage, without this piece of paper. Are you sure it has never been issued? You can check at your town hall and ask for a second certificate if the original was issued but you don't have a copy of it.
As joanmalaga advised, you should get a lawyer to assist you. Good luck.