Lawmakers are calling for changes to a state program that awards tax credits to investors who put their money into businesses in low-income communities. The legislators’ scrutiny comes after a Maine Sunday Telegram investigation revealed that Maine taxpayers will dole out $16 million in tax refunds for investments that never flowed to a now-shuttered in East Millinocket paper mill. The program, Maine New Markets Capital Investment, was created in 2011 to channel money from investors into eligible businesses.