There are many places in Arillas that can organise a Taxi for you but if you want to deal direct then suggest you contact:-
www.corfuholidaytaxi.comTheir English language is good. Expect a quote of around e56 depending where you are going.
If you are staying in Arillas and have contact details of the apt/Hotel owners it is always possible that they will arrange a transfer for you.
And.... do not forget the idea of a minibus share.
Cheers
Negg