Low speed gear issues DCT

[13 NF]

Hi my 2011 (December) M3 with DCT

The 1st gear appears to almost stall the car, very bad when cold.

The car appears to slip its clutch when trying to accelerate at low speed, occasionally at higher speed.

Not great trying to park either. It has done 15000 miles and is around 1500 miles off its first service.

Any ideas to point the dealer in right direction.

Thanks