A friend ships oil back to family in the UK every year and he uses Nomad's Crete Express Service
. They deliver from their base in Vamos near Chania to their base in Peterborough. They will collect from an address at this end and deliver to an address at the other but obviously charge extra. He has found it cheaper to use a courier at the UK end to collect from their depot and deliver to his family.
It might also be worth talking to Greengibble
who are based in Kefalas quite close to Vamos. They are not really a courier service but he makes regular trips to the UK to buy stock for his English shop in Crete. Typically he would go back empty so anything he can get paid to take back is a bonus. I would tend to phone rather than email.
If you know of an English shop down your end it might be worth contacting them.