Who must fix the phonescreen now?

I took my phone in for repairs last month. Last week my phone was sent back to the store unfixed claiming that the screen was cracked. When I took the phone in, it had a hard plastic screen protector which had a crack on it and the lady from Ackermans noted it. The person who came to collect the phone said the phone was in good condition( got a copy of the paperwork). When I went to collect my phone, there was no hard plastic screen protector, just the plastic film and the phone and screen was shattered. So clearly between the courier and the service place someone messed with my phone...