Below standard repair parts after accident

I had an accident in 2018. My car was taken in for repairs. The repairs included the windscreen. Miway authorised for a below quality cheap windscreen. I complained about it at the time and it was never resolved. The windscreen started cracking not long after. The repair garage said they can't help because this is what miway paid for. Now my windscreen is completely cracked and I must pay another excess to have it fixed.