VTT Core Return process is as follows. 

• Cores must be returned in 30 days an order to collect full core refund. 30-45 days 75% refund, 45-60 days 50% refund, after 60 days core charge is forfeit.
• Cores must be returned in undamaged condition, if damage occurs in shipping, due to poor packing or other reasons we reserve the right to prorate or forfeit core refund at our discretion. (this is most important for N55 cores as they are VERY fragile
• If cores are returned on time and undamaged, you will receive your core refund within 30 days via the method of our choice, paypal, check, etc.