Repairer uses my warranty to fix their mistakes

Samsung Galaxy S5<br> On January 5 2016 my phone was handed in for not reading the sim and tuning on and off involuntarily <br> Phone was repaired (at leisure) under warranty and returned to me <br> <br> Much was my surprise when my phone had to go in for another claim and I was told that both (2) mt claims was used on the first repair <br> <br> On Wednesday 29 march 2016 , I phoned customer care and after holding on for over 15 minutes, I was informed that the repaier ( cellclinc) used my screen repair , because they cracked the screen <br> <br> I was promised a call back from someone to resolve this matter , but until today nothing has happened <br> <br> I am highly dissatisfied with the level of service from such a mult-national company