From Brenda's comment----IF there really were felony charges against you, you would NOT be warned that a summons is coming. Also debt is CIVIL and is not a felony (and there is no jail or arrest that will happen). Note jd's comment below yours - they "hung up when I started to question her". Would a real, legitimate company do that??
The Atlanta Georgia area is loaded with bottom feeders. Nothing that is MAILED and in WRITING equals northing but threats (which are also illegal).