The woes pronounced against Chorazin and Bethsaida are because of the refusal of the people in them to repent. The people of these towns did believe in the miracles, but this belief did not translate into a change of mind, which was the primary purpose of the miracles that Jesus worked. Also, the Gentile cities of Tyre, Sidon that were regarded as biblical symbols of evil would fare better on the day of judgement that Chorazin and Bethsaida.
The miraculous and extra-ordinary cannot always sustain faith, which is a gift from God to anyone who wants to receive it and is willing to open the heart and mind. More often than not a kind word or a gentle touch can lead people to repentance.