Grove City / Mercer (Pennsylvania) KOA owner, Marty Henion was very rude to his customer. Upon arrival Friday night with receipt in hand, I checked in at the office. I was presented with a cash register receipt and told to sign. I read the receipt and noted that it did not state that I had a zero balance. I showed my printed receipt from my internet payment explaining that I was pre-paid and paid in full, and that I should not have to sign another slip. The owner, Marty Henion, spoke very curtly telling me "The signature is for liability, you'll sign the slip, or you'll leave." Well I did sign the slip with hesitation, and made a note of the owner's name and the manner in which he spoke to me. The rest of the weekend, Marty saw me 3 more times and never appologized for his very offensive tone. Instead of paying $42.00 per night for this KOA with a bad attitude, I recommend RV Village in Mercer. I called RV Village today and confirmed their rate of $22.00 per night full hook up, and no add'l cost for children.