Hi and welcome, I though I already answered to this topic
There are several options, have you considered Malaga car hire
or a private airport transfer
?, taxi cost would be between 30 and 40 Euro; for the same cost you can hire a Malaga airport transfer and for a little more a car rental for a week.
Other option would be the train to Fuengirola and taking a taxi from Fuengirola to Mijas.
Hope to be of help!