DB07P1

recently had the pipe from the master cylinder to slave cylinder replaced as it had split and had new pressure in the clutch (recovery job) anyhow i had to get it done by someone local instead of RE motorsport where it normally goes.it had to go re to get oil change as its just had new closed deck put in....when it was there i told him about the clutch and rick said he wasnt happy as there was too much free play on the clutch...so he tightened it a bit and off i went ....however iv now noticed that after around 20 minutes of driving the clutch will go stiffer and biting point seems to change..its not when its warmed up but after its been warmed up for quite a bit,and the other night i noticed the clutch was slipping..it doesnt seem to do it all the time but about 60% of the time when on full boost.
only had clutch replaced 9 months ago, and it hasnt taken much stick
any ideas guys?