Sounds like use of aileron differential is needed. At low speed, down ail. has more drag than up making it try to turn in that direction. Called adverse yaw. If you can give the ailerons about twice as much up as down.

you can do this on a computer radio or at the servo wheel on non computer radios move linkage from neutral 90 setting on wheel to another hole.if servo is on bottom of wing and you want more up than down thro move linkage one hole toward airleron and readjust clevis for neutral.you will now get more up than down .keep trying different holes till you get the differential you want.