If you have not had it for longer than the return policy of the seller, contact the seller and arrange for a return or exchange due the the lens being defective. Otherwise, sending it in to Precision will be your best timely move. Per the quote below, you can send it in without doing anything online. Make sure you include a phone number for them to use as an id when you look for repair status online at their website after they have received it, including area code. Fedex is a carrier that I have used effectively. The quote I referred to is below. When I have sent things in I have included a receipt copy, Pentax warranty copy, and copy of serial no. card to be on the safe side.
Quote
"If this is covered under a manufacture warranty please include a copy of your sales receipt with your first and last name on it to validate the age of equipment and we will bill your manufacture.
If you would like to send your camera in for repair, please provide your name, address, and contact information. As well as the make model and serial number of the unit, and a detailed description of the issue the equipment is having. Remove all accessories from your camera unless you feel they may be part of the problem. Wrap your information around the camera and secure with an elastic band.
Barring any unforeseen issues the turn time on repair is 5 to 7 business days.
You can ship the camera to or drop off your unit at:
Precision Camera Repair
7 Anngina Drive
Enfield, CT 06082
Monday - Friday - 9am - 5pm"
End Quote
Last edited by C_Jones; 07-15-2016 at 05:19 PM.