Complex sentence: On March 20,2012, WBNX activated a new subchannel (30.3 digital/55.3 virtual), then on March 26,2012, channel 55.3 became the new Cleveland affiliate of the MGM TV and movie network This TV, which was previously on WUAB.
Split into simpler sentences: On March 20,2012, WBNX activated a new subchannel (30.3 digital/55.3 virtual). Then, on March 26,2012, channel 55.3 became the new Cleveland affiliate of the MGM TV and movie network This TV, which was previously on WUAB.