CBS Local — A woman in South Carolina got quite a surprise after opening a package she thought contained a yoga mat she had ordered, but found nearly 20,000 illegal pills valued at $400,000 instead.

According to local police, the Rock Hill resident was waiting for her package on Sept. 30 when her mailman handed her a box around 2 p.m. local time. The woman, who chose to remain anonymous, discovered two bags full of narcotics in the package and immediately called the Rock Hill Police Department. The homeowner reportedly told officers that she did not know why someone would use her name and address to ship drugs.

The county’s drug unit commander, Marvin Brown, believes the package was probably sent there to be picked up by a waiting dealer. Brown said that the perfect place for drug pickups are, “vacant apartments [and] homes where people have gone to work for the day.”

The drugs were actually sent to the woman’s old house, which is still vacant, but because the address was misspelled the package was re-routed using her name. “The dealers weren’t as intelligent as they thought they were,” Commander Brown added.

Authorities say each oxycodone-type pill had a street value of about $20, making the total drug bust worth as much as $400,000. Police are reportedly working to trace the botched delivery back to the person in California who sent it.