I ordered a taxi on Saturday 13th Nov to go a distance of just under 2.5 miles (according to Google). The outward fare, at 19:30, was just under £6 and the return fare at 22:00 was just over £11 or double the outward fare. Following discussion with Gloucester City Council, it seems as if there's a loop hole where a taxi firm can take you to your destination in a taxi, but the return trip is via a Private Hire Vehicle. Although the same taxi firm, the PHV's can charge what they like and are outwith the Council control. Beware of what seems like a scam to me.