I am surprised another company would have your home telephone number and would contact you at home for a reference. I do not think you will find your ex employer has committed any actionable offence by sending a reference that appeared to come from you when it did not, a reference is given by the employer who take responsibility for what is said, not the person who wrote the reference. If you wish to make it clear you did not give the reference you can write to the other company and say the reference did not come from you, but I would caution against saying any more particularly that you do not agree with the content of the reference.