Complex sentence: Thr first, a Sainsbury's SavaCentre hypermarket was replaced by Asda in 2004, and the then Allders was replaced with a Debenhams store in 2005.
Split into simpler sentences: Thr first, a Sainsbury's SavaCentre hypermarket was replaced with an Asda store in 2004. The then Allders was replaced with a Debenhams store in 2005.