Songbird Garden Unrequested product substitution; won't pay full return Cape Fair, Missouri

I ordered peanut boost "ball" plugs that are about 3" in diameter.  They sent suet dough plugs that are about 1 1/4 " in diameter.  They do not fit my bird feeder.  They said they had the right to make substitutes if the first product was not available.  I told them they should have notified me first as I would have cancelled the order.  First they said they could charge a restocking fee if I returned them.  They refused to pay the return postage and said they would give me a store credit instead.  I am out $70.00 unless my credit card company can get it back.  They sould be put out of business.