To get the achievment All's Fare in Love and War you have to buy the Downtown Cab Company with Franklin. Eventually you will receive a call and a missions becomes available (shown by a flashing P on the map).
When I received this call I drove to the P on the map in a cab. Then I accidently accepted a cab fare and the P disappeared.
My question is whether I will get another call or another chance to complete this mission and get the achievement?